Maximum Flow and Minimum-Cost Flow in Almost-Linear Time
2022 IEEE 63rd Annual Symposium on Foundations of Computer Science (FOCS), 2022 · paper · Computer science
Gives an algorithm computing exact maximum and minimum-cost flows on directed graphs with m edges in m^(1+o(1)) time. It builds the flow through approximate minimum-ratio cycles using a new dynamic data structure, and extends to other convex flow problems.
Checked: PDF from arxiv.org, fetched 4 Oct 2026. Page numbers are those of that PDF.
35 findings
Substance Theorem 4.3 prints "The algorithm runs for Õ(mκ²) iterations" and "At the end of Õ(mκ²) iterations", but the text below it, the proof (p.33) and Sec. 9 (p.73) give Õ(mκ⁻²).
- p. 28 Theorem 4.3, preamble
The algorithm runs for eO(mκ2) iterations.
- p. 28 Theorem 4.3, item 3
At the end of eO(mκ2) iterations
- p. 28 Text after Theorem 4.3
within eO(mκ−2) iterations
- p. 73 Section 9
high accuracy in eO(mκ−2) iterations
Judge's note: Checked p.28: the theorem preamble and item 3 both show mκ² with a positive exponent, while the paragraph right below shows Õ(mκ⁻²) twice. The proof on p.33 says "the algorithm takes Õ(mκ⁻²) total iterations", and p.73 says "Õ(mκ⁻²) iterations". Lemma 4.4 gives a drop of κ²/500 per step, and the potential falls from at most 200m log mU to −O(m log m). That requires Õ(m/κ²) steps. The exponent in the theorem statement has the wrong sign.
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Substance Theorem 4.3 claims item 1 (g̃ᵀ(f*−f)/(100m+‖L̃(f*−f)‖1) ≤ −α/4) "For all κ ∈ (0,1)" with gradient error ≤ κ/8, but the proof's only support, Lemma 4.7, requires error ε < α/2, i.e. κ < 4α.
- p. 28 Theorem 4.3 hypotheses and item 1
For all κ ∈(0, 1), there is a potential reduction interior point method
- p. 31 Lemma 4.7 hypothesis
≤ε for some ε < α/2,
- p. 33 Proof of Theorem 4.3
The first item follows from Lemma 4.7.
Only the authors can say what is right here.
Judge's note: Checked pp.28, 31 and 33. The proof says only "The first item follows from Lemma 4.7", and Lemma 4.7 assumes ‖L⁻¹(g̃−g)‖∞ ≤ ε < α/2, with α = 1/(1000 log mU). My reworking: set g̃ = g + (κ/8)ℓ∘sign(f*−f). This is allowed, since the error is exactly κ/8. It gives g̃ᵀ(f*−f) = gᵀ(f*−f) + (κ/8)‖L(f*−f)‖1. I checked the reviewer's instance against the theorem's hypotheses: two parallel arcs a→b, U=100, c=(−1,0), f*=(100,−100), f0=(−99.99, 99.99). Then Φ ≈ 216 ≤ 2119, ℓ_e ≈ 100.09, ‖L(f*−f)‖1 ≈ 40034 and gᵀ(f*−f) ≈ −47.6. With κ=1/2 and ℓ̃=ℓ, g̃ᵀ(f*−f) ≈ 2455 > 0, so item 1 fails. Section 9 applies the theorem with error ακ/100 (Lemma 9.1), which is below α/2, so later uses meet Lemma 4.7's condition. The theorem as stated is too general; only the authors can say which restriction they intend.
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Substance Section 10.1 defines "X_e := {(f, y) : y < h_e(f)}" and eq. (46) minimizes 1⊤y over "y_e ≤ h(f_e)"; Theorem 10.13 uses the domain "{(f, y) : y ≤ h_e(f)}". These are hypographs; the reformulation requires the epigraph y ≥ h_e(f), as used in Theorem 10.14 ("{(x, y) : y ≥ |x|^p}"). The strict '<' in X_e also conflicts with '≤' elsewhere.
- p. 75 Section 10.1, definition of X_e and Eq. (46)
Xe def = {(f, y) : y < he(f)}:
- p. 75 Eq. (46), middle constraint
y∈RE:ye≤h(fe) for all e∈E
- p. 81 Theorem 10.13 statement
{(f, y) : y ≤he(f)} satisfying the guarantees of Assumption 10.2
- p. 82 Proof of Theorem 10.14
for the region {(x, y) : y ≥|x|p}
Judge's note: Seen on the PDF p.75, p.81 and p.82 images. Minimizing 1ᵀy subject to y_e ≤ h_e(f_e) is unbounded below, so eq. (46) is false as printed, and the hypograph of a convex h_e is generally not convex. Theorem 10.14 uses the barrier −2log y − log(y^{2/p} − x²) on y ≥ |x|^p, which confirms that the epigraph is intended. The fix is evident: reverse the inequalities.
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Substance Lemma 10.8 states 'For all e ∈ E, α−1ζe/4 is a self-concordant function', but the proof's bound α−1ζ''' ≤ 4(α−1ζ'')^{3/2}, together with 'Scaling by a factor of 4', gives self-concordance (constant 2) for 4α−1ζe, not for α−1ζe/4.
- p. 78 Lemma 10.8 and proof
For all e ∈E, α−1ζe/4 is a self-concordant function.
- p. 80 Lemma 10.10 proof
bζe(fe) = α−1ζe(fe)/4,
- p. 78 Lemma 10.8 statement and last line of proof
Lemma 10.8. For all e ∈E, α−1ζe/4 is a self-concordant function.
Only the authors can say what is right here.
Judge's note: Definition 10.1 (p.76) uses the standard constant 2: |∇³ψ[v,v,v]| ≤ 2(v⊤∇²ψ v)^{3/2}. The proof ends with g''' ≤ 4(g'')^{3/2} for g = α−1ζe. My reworking: if h = g/4, then h''' = g'''/4 ≤ (g'')^{3/2} = (4h'')^{3/2} = 8(h'')^{3/2}, which does not meet the constant 2. If h = 4g, then h''' ≤ 16(g'')^{3/2} = 16(h''/4)^{3/2} = 2(h'')^{3/2}, which does. So the stated scaling is not supported by the proof. Lemma 10.10 (p.80) and Lemma 10.11 (p.81) rely on this scaled function. Most likely the fix only changes constants, but the lemma as printed is left without a proof.
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Substance Lemma 10.9 states 'Zt(f∗t) − F∗ ≤ 4m', and its proof ends 'Zt(f) ≤ t·1⊤y + Σ exp(αψe(fe, ye)) ≤ tβQ + 2m ≤ 4m'. But Zt contains t·1⊤y, so t·1⊤y = tF∗ + tβQ, and the term tF∗ is dropped. The comparable quantity is Zt − tF∗.
- p. 79 Lemma 10.9
Zt(f ∗ t ) −F ∗≤4m.
- p. 79 Lemma 10.9 statement and final display of proof
exp(αψe(fe, ye)) ≤tβQ + 2m ≤4m.
Only the authors can say what is right here.
Judge's note: Checked on the PDF p.79 image. With y = βy(0) + (1−β)y∗ and Q defined as the optimality gap h(f(0)) − F∗, we get t·1⊤y = tF∗ + tβQ, not ≤ tβQ. The definition of F∗ (p.75) does not normalise it to 0. In Lemma 10.10 (p.80), the step '(Zt(f∗t) − F∗) − (Zt(f) − F∗) ≤ 4m − t·10m/t' is consistent only if F∗ is read as tF∗. As printed, the lemma's bound fails whenever F∗ > 0 and t > 1. Reading it as Zt − tF∗ appears to repair the argument, but only the authors can confirm the intended statement.
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Substance The matrix-scaling objective is printed as 'Σ Aij exp(xi − yj) − Σ xi − Σ yi', and its reformulation as 'Σ we exp(zi − zj) − Σ_{i=1}^{2n} zi'. Both have the wrong sign on the y (second-half) terms, which is inconsistent with the stated optimality condition B⊤W exp(Bz) = d, where d is +1 on {1..n} and −1 on {n+1..2n}.
- p. 83 Section 10.2, matrix scaling
Then the above problem becomes P e∈E(G) we exp(zi −zj) −P2n i=1 zi.
- p. 83 Section 10.2
where d is +1 on the vertices {1, . . . , n} and −1 on {n + 1, . . . , 2n}
- p. 83 Section 10.2, matrix scaling objective
Aij exp(xi −yj) −
- p. 83 Section 10.2, reformulated objective
we exp(zi −zj) −P2n
Judge's note: Checked on the PDF p.83 image: both linear terms carry minus signs. My reworking: ∂/∂yj = −Σi Aij e^{xi−yj} − 1. This is strictly negative, so there is no stationary point, and the objective tends to −∞ as yj → ∞. For the reformulated objective, stationarity gives B⊤W exp(Bz) = 1 (all ones), not the stated d. The stated d and the doubly-stochastic condition require the linear term −d⊤z, i.e. −Σxi + Σyj. This is evident from the paper's own text, without relying on [CMTV17].
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Reference or label The negative shortest-paths paragraph says "by invoking Corollary 1.2 with costs set to edge weights, u⁻ = 0, u⁺ = n·1 and d_s = n ...". Corollary 1.2 is the max-flow result (capacities in [1,U], no costs). A reduction with costs, demands and lower capacities needs the min-cost flow result, Theorem 1.1.
- p. 111 Appendix D, Negative Shortest-Paths
by invoking Corollary 1.2 with costs set to edge weights
- p. 5 Corollary 1.2
computes a maximum flow between two vertices in time m1+o(1) log U
Judge's note: Checked Corollary 1.2 on p.5 (max-flow between two vertices, m^{1+o(1)} log U time) and the paragraph on p.111. Section 1.1 attributes these applications to Theorem 1.1 'by standard reductions'. The pointer is to the wrong statement.
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Reference or label p.50: "This is not sufficient to show Definition 6.1, which only guarantees that the latter quality is at most −α". The ⟨g,c⟩/‖w‖₁ ≤ −α condition is part of Theorem 6.2, not Definition 6.1.
- p. 50 Text after Theorem 7.1
This is not sufficient to show Definition 6.1, which only guarantees that the latter quality is at most −α
Judge's note: I read Definition 6.1 on p.44: items 1–4 cover circulation, length bound, stability and quasipolynomial bounds, and there is no α. The condition ⟨g^{(t)},c^{(t)}⟩/‖w^{(t)}‖₁ ≤ −α appears in the Update operation of Theorem 6.2 (p.45). The intended reference is very likely Theorem 6.2.
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Reference or label Algorithm 4 caption reads "Dynamically maintains a sparsified core graph (Definition 6.7)", but the sparsified core graph is Definition 6.9 (Definition 6.7 is the core graph).
- p. 55 Algorithm 4 caption
Dynamically maintains a sparsified core graph (Definition 6.7)
Judge's note: Page 55 image shows the caption citing Definition 6.7. Lemma 7.7 and Lemma 7.8 cite Definition 6.9 for the sparsified core graph S(G,F), and Definition 7.6 refers to the core graph C(G,F) separately. The pointer should be 6.9.
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Reference or label Subcase 2B: "recall that we already dealt with established Condition (36) for l < i above in Equation (39)"; levels l < i were handled in the common part of Case 2 before Eq. (37), and Eq. (39) concerns j ∈ {i,…,d} in Subcase 2A. The sentence also contains the garbled 'dealt with established'.
- p. 69 Proof of Lemma 8.5, Subcase 2B
recall that we already dealt with established Condition (36) for l < i above in Equa- tion (39).
Judge's note: Page 68 image: the 'To start, we deal with levels l < i' paragraph comes before (37). Page 69 image: (39) is the 'for all j ∈ {i,…,d} there exists l < j' statement. The pointer is wrong.
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Reference or label "This allows us to prove that MinCostFlow satisfies the hypotheses of Algorithm 7" should read "Theorem 4.3". MinCostFlow is Algorithm 7, and the proof of Lemma 9.3 says it "satisfies the hypotheses of Theorem 4.3".
- p. 74 Text before Lemma 9.3
satisfies the hypotheses of Algorithm 7, and allows us to bound the total number of iterations.
- p. 74 end of proof of Lemma 9.2
MinCostFlow satisfies the hypotheses of Algorithm 7
- p. 74 paragraph between Lemma 9.2 and Lemma 9.3
This allows us to prove that MinCostFlow satisfies the hypotheses of Algorithm 7
Judge's note: On the PDF p.74 image the sentence before Lemma 9.3 cites Algorithm 7, while the proof of Lemma 9.3 directly below and the section intro (PDF p.73) both refer to the hypotheses of Theorem 4.3.
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Reference or label [AS20] gives the venue as "Proceedings of the Fourteenth Annual ACM-SIAM Symposium on Discrete Algorithms. SIAM. 2020", but the same reference list gives the 2019 symposium as the "Thirtieth" ([AKPS19]).
- p. 85 Reference [AS20]
Proceedings of the Fourteenth Annual ACM-SIAM Sym- posium on Discrete Algorithms. SIAM. 2020
- p. 84 Reference [AKPS19]
Proceedings of the Thirtieth Annual ACM- SIAM Symposium on Discrete Algorithms. SIAM. 2019
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: that SODA is held once a year, so the 2020 meeting is the Thirty-First. Page images p85 ([AS20]: 'Fourteenth ... 2020') and p84 ([AKPS19]: 'Thirtieth ... 2019') match the quotes. Within the list itself, a 2020 meeting cannot be the Fourteenth if the 2019 meeting was the Thirtieth.
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Reference or label Reference [BK04] (Boykov–Kolmogorov, IEEE TPAMI 26.9, 2004) gives 'Available at: https://arxiv.org/abs/1202.3367', the same arXiv URL that [KMP12] (Kelner–Miller–Peng, STOC 2012) gives.
- p. 85 Reference [BK04]
Available at: https://arxiv.org/abs/ 1202.3367, pp. 1124–1137
- p. 90 Reference [KMP12]
Available at: https://arxiv.org/abs/1202.3367.
- p. 85 Reference list, [BK04]
Available at: https://arxiv.org/abs/ 1202.3367
- p. 90 Reference list, [KMP12]
Available at: https://arxiv.org/abs/1202.3367
Judge's note: Checked on the PDF p.85 and p.90 crops: both entries print arxiv.org/abs/1202.3367. Two unrelated works cannot share one arXiv identifier. A 2012-numbered arXiv ID (format YYMM.NNNNN) fits the 2012 KMP12 paper, not a 2004 journal article. The URL in [BK04] therefore appears to be the misplaced one.
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Wording In the Warm-Up chain "g⊤Δ*/‖LΔ*‖1 ≥ 1/γ · Σ Δ*e g⊤p(...) / Σ Δ*e ‖L p(...)‖1 ≥ 1/γ min ...", the factor should be γ, not 1/γ.
- p. 10 Section 2.2, Warm-Up displayed inequality
≥ 1/γ ·
Only the authors can say what is right here.
Judge's note: I reworked the step. Let N = g⊤Δ* < 0 (the paper says it is negative) and D = Σ Δ*_e ‖L p(e⊕T)‖1. By the stretch bound, ‖LΔ*‖1 ≥ D/γ, so 1/‖LΔ*‖1 ≤ γ/D. Multiplying by N < 0 gives N/‖LΔ*‖1 ≥ γN/D. The triangle inequality gives ‖LΔ*‖1 ≤ D, so N/‖LΔ*‖1 ≤ N/D ≤ (1/γ)N/D for γ ≥ 1. The printed first inequality therefore fails unless everything is equal. Counterexample: N = −1, D = ‖LΔ*‖1 = 1, γ = 2 gives −1 ≥ −0.5, which is false. With γ in place of 1/γ, the chain gives the γ-approximation the next sentence states, so the stated conclusion stands.
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Wording Section 2.5 states the condition reversed: "as long as the width of w(f+Δ) has not increased significantly, i.e. ‖w(f+Δ)‖1 ≤ Õ(1)‖w(f)‖1" and "‖w(f+Δ)‖1 ≥ 100‖w(f)‖1 must hold", whereas the derivation requires that the width has not decreased.
- p. 18 Section 2.5, paragraphs after the min_j bound
has not increased significantly
- p. 18 Section 2.5
≥ 100 ∥w(f)∥1 must hold
- p. 13 Section 2.2, last paragraph
significantly less than the value
Only the authors can say what is right here.
Judge's note: I reworked the step. The bound just derived is min_j ‖str∘w(f+Δ)‖1 ≲ Õ(1)‖w(f)‖1 + ‖w(f+Δ)‖1. Condition (6) at f+Δ needs this to be ≤ Õ(1)‖w(f+Δ)‖1. That holds when ‖w(f)‖1 ≤ Õ(1)‖w(f+Δ)‖1, and it holds automatically if the width increases. The failure case is therefore ‖w(f)‖1 ≥ 100‖w(f+Δ)‖1, a decrease. This matches the next sentence ('each recomputation reduces the ℓ1 norm of the width by a constant factor') and p.13 ('significantly less than the value when ... last rebuilt'). The overview inequalities are reversed. The formal results are unaffected.
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Wording Algorithm 7 line 27 scales Δ so that "⟨g(t), ∆⟩ = −κ²α²/800", but the proof of Lemma 9.3 invokes "Theorem 4.3 (where we change κ to ακ/8 for this setting)", whose item 2 uses "η ← κ²/(50·|g̃∆|)", i.e. (ακ/8)²/50 = α²κ²/3200. The same proof checks the gradient error as "≤ (1 + ε)ακ/100 ≤ ακ/50", while Theorem 4.3 with κ→ακ/8 requires ≤ ακ/64.
- p. 72 Algorithm 7, line 27
Scale ∆so ⟨g(t), ∆⟩= −κ2α2/800
- p. 74 Proof of Lemma 9.3
Theorem 4.3 (where we change κ to ακ/8 for this setting)
- p. 28 Theorem 4.3 item 2
for η ←κ2/(50 · |eg∆|)
- p. 74 Proof of Lemma 9.3
≤(1 + ε)ακ/100 ≤ακ/50,
Only the authors can say what is right here.
Judge's note: Checked Theorem 4.3 and Lemma 4.4 (PDF p.28): η g̃ᵀΔ = −κ²/50 and ‖L⁻¹(g̃−g)‖∞ ≤ κ/8. Eq. (45) (PDF p.74) gives ratio ≤ −κα/8, so κ' = ακ/8. Then (i) the required step is α²κ²/3200, while Algorithm 7 (PDF p.72) uses α²κ²/800, which corresponds to κ' = ακ/4. (ii) The required error bound is κ'/8 = ακ/64, and the printed weakening to ακ/50 exceeds it, although the unweakened (1+ε)ακ/100 would meet it. The scaling r/(cᵀf−F*) between g and g̃ is ≈1 and does not explain a factor of 4. These are constant-level mismatches; the Õ(mκ⁻²α⁻²) result appears to stand once constants are adjusted. Only the authors can say which constant was intended.
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Wording Proof of Lemma 4.6 (p.29) cites "the Taylor expansion log(1 + z) = Σ_{k≥0} z^k/k for |z| < 1", which is wrong: the k=0 term is undefined, the alternating sign is missing, and the correct series is Σ_{k≥1} (−1)^{k+1} z^k/k.
- p. 29 Proof of Lemma 4.6
Taylor expansion log(1 + z) = P k≥0 zk/k for |z| < 1
- p. 29 Proof of Lemma 4.6
Taylor expansion log(1 + z) = P k≥0 zk/k for |z| < 1.
- p. 29 Proof of Lemma 4.6
log(1 + z) = P k≥0 zk/k
- p. 29 Proof of Lemma 4.6
log(1 + z) = P
Only the authors can say what is right here.
Judge's note: The full-page image of p.29 shows Σ_{k≥0} z^k/k. Reworked: Σ_{k≥1} z^k/k equals −log(1−z), not log(1+z). At z=0.1 it is ≈0.1053, whereas log(1.1) ≈ 0.0953. Inequality (16) still holds, because log(1+z) ≤ z ≤ z+z², so the faulty step leaves the stated lemma standing.
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Wording Final display of the proof of Lemma 4.4: "ακ/10·‖L(f)Δ̄‖₁ ≤ −κ²/100 + κ²/10000 + ακ/250 ≤ −κ²/500". By (21) the term is ακ²/250, and with the printed ακ/250 the last inequality fails when κ is small relative to α.
- p. 30 Proof of Lemma 4.4, final display
ακ/10 · L(f)∆ 1 (ii) ≤−κ2 100 + κ2 10000 + ακ 250 ≤−κ2 500.
- p. 30 Final display of proof of Lemma 4.4
κ2 10000 + ακ 250 ≤−κ2 500.
- p. 30 Proof of Lemma 4.4, last display
≤ −κ2/100 + κ2/10000 + ακ/250 ≤ −κ2/500
- p. 30 bound on |c⊤Δ̄|
κ/(500m)
Only the authors can say what is right here.
Judge's note: Page image p030 shows 'ακ/250' with no square. By (21), ‖L(f)Δ̄‖₁ ≤ κ/25, so (ακ/10)(κ/25) = ακ²/250. With ακ/250 the final inequality needs ακ/250 ≤ 0.0079κ², roughly κ ≥ α/2. Counterexample: at κ = α/4 the left side is +0.0061κ², which is greater than −0.002κ². With ακ²/250 the inequality holds for every κ, so the lemma stands but the printed step does not. The κ/(500m) bullet in this cluster is the defect already covered in C033.
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Wording Proof of Lemma 7.7 ends the validity chain with "≤ 2 Σ_{ê: ê'∈Π(ê)} w^{C(G,F)}_ê = 2w^{S(G,F)}_{ê'}", but Eq. (29) defines w^S_{e'} = 2 Σ w^C_ê |Π(ê)|, so the left side equals w^S_{e'}, not 2w^S_{e'}.
- p. 53 Proof of Lemma 7.7, validity chain
= 2wS(G,F) be′
- p. 53 Proof of Lemma 7.7, validity chain
= 2wS(G,F)
- p. 53 Definition 7.6, eq. (29)
wS(G,F) = 2 X
- p. 53 Definition 7.6, eq. (29)
wS(G,F) = 2
Only the authors can say what is right here.
Judge's note: Checked p.53 (printed p.50). Eq. (29): w^{S} = 2 Σ_ê w^C_ê |Π_{C→S}(ê)|. Evaluated at edge ê', the coordinate is 2 Σ_{ê: ê'∈Π(ê)} w^C_ê |Π(ê)_{ê'}|. Embedding paths are taken as simple, so each multiplicity is 1, and the coordinate is just 2 Σ w^C_ê. The last displayed equality '= 2w^S_{ê'}' therefore fails by a factor of 2 as printed, even though the text says it follows 'by the definition of w^S in (29)'. As printed, the chain only gives |ℓc| ≤ 2w^S. If the final term is w^S, the chain gives the claimed validity |ℓc| ≤ w^S, so the lemma stands and the step is faulty (S3).
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Wording Proof of Theorem 6.2 (p.68/PDF p.71) defines "κ := κ^(7.1)/(2d + 2)" but the display has "κ^(7.1)/(2d) ⟨g(t),c(t)⟩/‖w(t)‖1 ≤ −κα ≤ … ≤ κ^(7.1)·⟨g(t),c(t)⟩/Σ‖w(prev_i)‖1", and then concludes "Σ‖w(prev_i)‖1 ≥ 2(d+1)‖w(t)‖1"; the printed chain only yields the factor 2d.
- p. 71 Proof of Theorem 6.2
Let κ def = κ(7.1)/(2d + 2).
- p. 71 Proof of Theorem 6.2, display
κ(7.1) 2d ⟨g(t), c(t)⟩
- p. 71 Proof of Theorem 6.2, conclusion
≥2(d + 1)∥w(t)∥1
- p. 71 Proof of Theorem 6.2, displayed inequality
κ(7.1) 2d
Only the authors can say what is right here.
Judge's note: Checked on the page image. Reworking: ⟨g,c⟩<0. Dividing the outer inequality κ^(7.1)/(2d)·⟨g,c⟩/‖w‖ ≤ κ^(7.1)⟨g,c⟩/Σ by the negative number κ^(7.1)⟨g,c⟩ gives Σ ≥ 2d‖w‖, not 2(d+1)‖w‖. With 2d+2 in the left factor (matching the definition of κ, and using ⟨g,c⟩/‖w‖ ≤ −α), the first inequality holds with equality on the bound and gives Σ ≥ (2d+2)‖w‖, as claimed. So the step is wrong as printed (likely a dropped '+2'), but the stated result stands with the evident constant.
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Wording Proof of Lemma 9.1: "Because we have argue above that ‖L(f(t))^{−1}(f(t) − f̃(t))‖∞ ≤ sε". The previous paragraph established ‖L(f(t))(f(t) − f̃(t))‖∞ ≤ sε, which is the form Lemma 4.10 requires. The section intro also has "In this section we given the full pseudocode".
- p. 73 Proof of Lemma 9.1
Because we have argue above that ∥L(f (t))−1(f (t) −ef (t))∥∞≤sε
- p. 71 Sec 9 intro
In this section we given the full pseudocode
- p. 73 proof of Lemma 9.1
Because we have argue above
Judge's note: On the PDF p.73 image the first paragraph of the proof has L(f(t))(f(t)−f̃(t)) without an inverse, while the second paragraph has L(f(t))^{−1}. Lemma 4.10's hypothesis (text p.33) is ‖L(f)(f−f̄)‖∞ ≤ ε, so the inverse is a slip. The grammar slips 'argue'→'argued' (p.73) and 'given'→'give' (PDF p.71) are also present.
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Wording Proof of Lemma 9.1 applies Lemma 4.8 as "|c⊤∆|/(c⊤f(t) − F∗) ≤ |g(t)∆|/(κm) ≤ α²κ/(800m) ≤ 1/(800m)" with ratio κ, but the D(HSFC).Query() guarantee used (eq. (45)) is "≤ −κα/8".
- p. 73 Proof of Lemma 9.1
c⊤f (t) −F ∗≤|g(t)∆|/(κm) ≤α2κ/(800m) ≤1/(800m),
- p. 74 Eq. (45)
≤−κα/8.
Only the authors can say what is right here.
Judge's note: Lemma 4.8 (text p.29) gives |cᵀΔ|/(cᵀf−F*) ≤ |g̃ᵀΔ|/(κ'm) when g̃ᵀΔ/‖L̃Δ‖1 ≤ −κ'. Eq. (45) (PDF p.74) supplies κ' = κα/8, not κ. Reworking: (κ²α²/800)/((κα/8)m) = κα/(100m), not α²κ/(800m). Since κα is tiny (α = 1/(1000 log mU), κ = m^{−o(1)}), κα/(100m) ≤ 1/(800m) still holds, so the lemma stands and only the intermediate step is faulty.
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Wording Proof of Lemma 9.2 (item 3): "|w_e(t) − w_e(t')| =(i) ℓ_e(t)|f_e(t) − f_e(t')|" states an equality where only ≤ holds.
- p. 73 Proof of Lemma 9.2, item 3
= ℓ(t)
Only the authors can say what is right here.
Judge's note: With w = 50 + |ℓ∘(f*−f)| and ℓ(t)=ℓ(t') (justification (i)), the reverse triangle inequality gives | |ℓ(f*−f(t))| − |ℓ(f*−f(t'))| | ≤ ℓ|f(t)−f(t')|. Counterexample: ℓ=1, f*−f(t)=1, f*−f(t')=−1 gives LHS 0 and RHS 2. The argument needs only ≤, so the result stands. Checked on the PDF p.73 image.
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Wording In the proof of Lemma 10.8, the expansion of α−1∇³(exp(αψe))[v,v,v] has the middle term '+ 3α∇2ψe(fe, ye(fe))[v, v]'. It is missing the factor ⟨∇ψe, v⟩.
- p. 78 Proof of Lemma 10.8
+ 3α∇2ψe(fe, ye(fe))[v, v] + α2⟨∇ψe(fe, ye(fe)), v⟩3
Only the authors can say what is right here.
Judge's note: Checked on the PDF p.78 image: the middle term is printed only as 3α∇²ψe(...)[v,v]. My reworking along direction v, with h = e^{αψ}: h' = αψ'h, h'' = (αψ'' + α²ψ'²)h, h''' = (αψ''' + 3α²ψ'ψ'' + α³ψ'³)h. Dividing by α gives a middle term of 3α ψ''ψ' = 3α∇²ψ[v,v]⟨∇ψ,v⟩. The printed term is also only quadratic in v while the other terms are cubic. The ν-self-concordance bound that follows handles the correct term in the same way, so the step is faulty but the lemma's bound is not affected by this slip.
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Wording In the proof of Lemma 10.10, '4α(... − √(ζ̂''e(fe))|[f∗t]e − fe| + 1)' is set equal to '... − α/2 · ℓ(fe)|[f∗t]e − fe| + 4α'. With ζ̂e = α−1ζe/4 and ℓ = √(α−1ζ''), 4α√ζ̂'' = 2αℓ, not αℓ/2.
- p. 80 Proof of Lemma 10.10, rearranged inequality
−α/2 · ℓ(fe)|[f ∗ t ]e −fe| + 4α.
- p. 80 Proof of Lemma 10.10, 'Rearranging' display
t ]e −fe) −α/2 · ℓ(fe)|[f ∗
Only the authors can say what is right here.
Judge's note: Checked on the PDF p.80 image: the display uses '='. ℓ(f)e = √(α−1ζ''e) (eq. 53, p.79). ζ̂'' = α−1ζ''/4, so √ζ̂'' = ℓ/2 and 4α·ℓ/2 = 2αℓ. The equality as printed is false. Because 2αℓ ≥ αℓ/2, the version with −α/2 still holds as an inequality, so the lemma's conclusion survives (subject to C092). The value α/2 is what one gets if ζ̂ = 4α−1ζ, which is consistent with C092.
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Wording In the proof of Lemma 10.10, the error term is written '∥L(f)−1(f∗t − f)∥1∥L(f)(eg − g(f))∥∞', with L and L−1 swapped. The first-case display also bounds 'g(f)⊤(f∗t − f) ≤ g(f)⊤(f∗t − f) + …' where the left side should be g̃⊤(f∗t − f).
- p. 80 Proof of Lemma 10.10, second case
∥L(f)−1(f ∗ t −f)∥1∥L(f)(eg −g(f))∥∞
- p. 80 Proof of Lemma 10.10, first case
g(f)⊤(f ∗ t −f) ≤g(f)⊤(f ∗ t −f) + ∥L(f)−1(eg −g(f))∥∞
- p. 80 Last display of proof of Lemma 10.10
t −f)∥1 + 4αm + ∥L(f)−1(f ∗
Only the authors can say what is right here.
Judge's note: Checked on the PDF p.80 image. The lemma's hypothesis controls ∥L(f)−1(g̃ − g(f))∥∞ ≤ ε, and the next line uses ε∥L(f)(f∗t − f)∥1. That requires the Hölder pairing ∥L(f)(f∗−f)∥1·∥L(f)−1(g̃−g)∥∞. The printed pairing is a valid Hölder bound, but it does not give the next line. In the first case, the left side g(f)⊤ repeats the right side, while the lemma bounds g̃⊤(f∗t − f). Both slips are evident transpositions, and the stated result stands once they are corrected.
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Wording The proof of Theorem 10.13 says 'the value of Zt decreases by κ−2α−2 = m−o(1) per iteration'. Since κ, α < 1, κ−2α−2 > 1 and is m^{+o(1)}. The decrease available from Lemma 10.12 is of order κ²α².
- p. 81 Proof of Theorem 10.13
the value of Zt decreases by κ−2α−2 = m−o(1) per iteration
- p. 81 Proof of Theorem 10.13
the value of Zt decreases by κ−2α−2 = m−o(1) per iteration.
- p. 81 Proof of Thm 10.13
decreases by κ−2α−2 = m−o(1) per iteration
Only the authors can say what is right here.
Judge's note: The PDF p.81 image shows negative exponents on κ and α, so this is not an extraction loss. Lemma 10.12 gives a decrease of κ²/100, with κ effectively scaled by α, so the decrease is of order κ²α² = m^{−o(1)}. As printed, the equality is false. The iteration count m^{1+o(1)} follows from the correct κ²α², so the theorem stands.
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Wording The proof of Lemma 10.12 writes the Taylor bound as 'φ(1) − φ(0) ≤ φ′(0) + max_{s∈[0,1]} φ′′(s)²/2'. The second-order remainder is max φ''(s)/2, not φ''(s)²/2.
- p. 81 Proof of Lemma 10.12
≤φ′(0) + max s∈[0,1] φ′′(s)2/2
Only the authors can say what is right here.
Judge's note: Checked on the PDF p.81 image: the square is printed. Taylor's theorem gives φ(1) = φ(0) + φ'(0) + φ''(ξ)/2 for some ξ in [0,1]. The next line correctly uses Δ̄⊤∇²Zt Δ̄, which corresponds to φ'' without a square. The rest of the step is unaffected.
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Wording The proof of Lemma 10.12 bounds ∥L(f)Δ̄∥1 by κ/50 in '≤ −κ2/50 + εκ/50 + (κ/50)2 ≤ −κ2/100'. The hypothesis L̃ ≈2 L(f) only gives ∥L(f)Δ̄∥1 ≤ 2∥L̃Δ̄∥1 ≤ κ/25.
- p. 81 Proof of Lemma 10.12, last line of chain
≤−κ2/50 + εκ/50 + (κ/50)2 ≤−κ2/100,
Only the authors can say what is right here.
Judge's note: Section 3 (p.~25) defines a ≈α b as α−1b ≤ a ≤ αb. From g̃⊤Δ/∥L̃Δ∥1 ≤ −κ and ηg̃⊤Δ = −κ²/50, we get ∥L̃Δ̄∥1 ≤ κ/50, and therefore ∥L(f)Δ̄∥1 ≤ κ/25. The analogous step in Section 4 (p.30) explicitly uses ∥L(f)Δ∥1 ≤ 2∥L̃Δ∥1. The printed step drops this factor. With it restored and ε < κ/100: −κ²/50 + εκ/25 + (κ/25)² ≤ −0.018κ² ≤ −κ²/100. So the lemma still holds, but the printed step is not justified as written.
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Wording In the proof of Lemma C.9, the rearrangement "−s^{+⊤}u = (By − s^− + s^+)^⊤ f = c^⊤ f" has the signs of s^− and s^+ flipped. From the preceding identity it should read (By + s^− − s^+)^⊤ f, which equals c^⊤ f by dual feasibility (59).
- p. 105 Proof of Lemma C.9, last display
−s+⊤u = (By −s−+ s+)⊤f = c⊤f,
- p. 105 proof of Lemma C.9, last display
−s+⊤u = (By −s−+ s+)⊤f = c⊤f
Only the authors can say what is right here.
Judge's note: I read the step on page image p105 (printed page 102); the signs are as quoted. My reworking: y^⊤B^⊤f + s^{−⊤}f + s^{+⊤}(u−f) = 0 gives −s^{+⊤}u = (By)^⊤f + s^{−⊤}f − s^{+⊤}f = (By + s^− − s^+)^⊤f. Constraint (59) is By + s^− − s^+ = c, which matches the per-arc form 'y_v − y_u + s^−_e − s^+_e = c_e' in the same proof. As printed, (By − s^− + s^+)^⊤f differs from (By + s^− − s^+)^⊤f by 2(s^− − s^+)^⊤f, so it does not equal c^⊤f in general. The conclusion c^⊤f = −s^{+⊤}u still holds.
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Wording Section C.2: "the optimal objective value on the residual graph is at most −0.1. This indicates that the value is 0". To exclude the alternative 'at most −1' and conclude the value is 0, it must be at least −0.1.
- p. 106 After Lemma C.10 statement
the optimal objective value on the residual graph is at most −0.1. This indicates that the value is 0
Judge's note: p106 (page 103) matches the quote. The next sentence says the value is either 0 or at most −1, so only a lower bound above −1 forces 0. The proof of Lemma C.10 on p109 (page 106) uses c^⊤(f* − f^(T)) ≥ −1/2, the 'at least' direction.
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Wording The prose before Def. C.12 says capacities are rounded to multiples of B/m^20 and the scheme will "remove edges of capacity over mB". Definition C.12 instead says "We include every arc e ∈ E to G^B" and caps u^B_e at "⌈Bm^20⌉ if u_e > Bm^20". The operation (remove vs cap) and the threshold (mB vs Bm^20) both differ.
- p. 107 Text before Definition C.12
remove edges of capacity over mB
- p. 107 Definition C.12
We include every arc e ∈E to GB
- p. 107 Def C.12
or ⌈Bm20⌉if ue > Bm20
- p. 107 Definition C.12
⌈Bm20⌉if ue > Bm20
Judge's note: Checked p.107 (printed p.104). The informal sentence and Definition C.12 disagree on what happens to large edges and on the threshold. Remark C.13 (capacities at most m^40 after scaling) and the proof of Lemma C.14 (f*_e ≤ ⌈Bm^20⌉) both follow the formal definition, so the prose sentence is the one out of line.
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Wording In the proof of Lemma C.14: "The cost of C_i is at least −1 due to integral costs." C_i is a negative-cost cycle with integer costs, so its cost is at most −1, which is what the next inequality needs.
- p. 108 Proof of Lemma C.14
The cost of Ci is at least −1 due to integral costs.
Only the authors can say what is right here.
Judge's note: Checked p.108. The next step deduces c^T f* < −⌈Bm^20⌉. Reworking it: this needs a*_i·c^T p(C_i) ≤ −a*_i < −⌈Bm^20⌉, plus the other cycle terms being non-positive. That requires c^T p(C_i) ≤ −1. A lower bound of −1 gives the inequality in the wrong direction. The proof of Lemma C.11 on p.107 states it correctly ('at most −1 because costs are integers'). The step is faulty as printed, but the claim stands with 'at most'.
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Wording In the proof of Lemma C.14: "If B < 2m^20, we have u^B = u because ⌈B/m^20⌉ = 1." This is false when m^20 < B < 2m^20.
- p. 108 Proof of Lemma C.14
If B < 2m20, we have uB = u because ⌈B/m20⌉= 1.
Only the authors can say what is right here.
Judge's note: Checked p.108. Lemma C.14 allows any B > 0. Counterexample: B = 1.5·m^20 gives B/m^20 = 1.5 and ⌈1.5⌉ = 2, not 1. The claim holds only for B ≤ m^20. The 'otherwise' branch uses ⌈B/m^20⌉ ≤ 2B/m^20, which holds for every B ≥ m^20. Splitting the cases at m^20 therefore repairs the proof, and the lemma's statement is unaffected.
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Wording The negative-cycle condition is reversed: "check whether the computed flow f is non-zero. If it is not then f is a negative cost circulation". It should say that a non-zero f is a negative-cost circulation.
- p. 111 Appendix D, Negative Shortest-Paths
check whether the computed flow f is non-zero. If it is not then f is a negative cost circulation
Judge's note: Checked p.111. 'If it is not [non-zero]' means f = 0, and a zero flow is not a negative-cost circulation. The intended reading is 'If it is'.
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72 minor (typos and the like; most checked by the judge only)
Reference or label Lemma 8.3 proof cites the fix cost "C_r m/k^i (Line 6)" and "a LOSS at some level i (Line 10)", but in Algorithm 6 the fixes are Lines 7 and 11; Lines 6 and 10 only select the level.
- p. 70 Proof of Lemma 8.3, WIN cost
Crm/ki (Line 6)
- p. 70 Proof of Lemma 8.3, LOSS cost
LOSS at some level i (Line 10)
- p. 65 Algorithm 6
Fix level i, thus rebuilding levels j ≥i.
Judge's note: Page 65 image shows Algorithm 6: Line 6 is 'Find the smallest level i', Line 7 is 'Fix level i'; Line 10 is 'Let i be the smallest level', Line 11 is 'Fix level i'. The page 69 outline uses the same Line 6/10 references. Lines 6/10 start the WIN/LOSS blocks, so the reference is loose rather than clearly wrong.
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Wording Section 1 defines "B((a,b),v) is 1 if v = a, −1 if v = b", but Appendix B.1 ("If d̄v > dv, then add an edge ev = (v → v*) ... set f_ev = d̄v − dv") and Lemma C.9 ("s−e = ce − (yv − yu)" with By + s− − s+ = c) use the opposite sign.
- p. 4 Section 1
B((a,b),v) is 1 if v = a, −1 if v = b
- p. 95 Appendix B.1
dv > dv, then add an edge ev = (v →v∗) with upper capacity 2(dv −dv)
- p. 105 Proof of Lemma C.9
If fe = 0, we set s− e = ce −(yv −yu)
Only the authors can say what is right here.
Judge's note: Section 1 (p.4) defines the matrix so that (B^T f)_v = outflow − inflow and (By)_(u,v) = y_u − y_v. B.1 (p.95): if d̄_v > d_v, an edge v→v* carrying d̄_v − d_v adds outflow at v, so (B^T f)_v becomes 2d̄_v − d_v, not d_v. Under the Section 1 convention the edge should point v*→v. C.9 (p.105): a valid distance label gives y_v − y_u ≤ c_e, written B(f)y ≤ c(f), so (By)_e = y_v − y_u. That is again the reversed sign. Appendix C only says the matrix 'respects the edge orientation' (p.103) and does not state a sign. Each argument works under the flipped convention, so the results stand. The text is still inconsistent with the definition the paper gives.
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Wording Isotonic regression is claimed "for all p ∈ [1, ∞]" in Section 1.1 and Theorem 10.15 but "for all p ∈ [1, ∞)" in Appendix D ("We give an almost linear time algorithm ... to Isotonic regression for all p ∈ [1, ∞)").
- p. 5 Section 1.1
p-norm isotonic regression for all p ∈[1, ∞]
- p. 83 Theorem 10.15
and p ∈[1, ∞], we can compute
- p. 112 Appendix D, Isotonic Regression
solution to Isotonic regression for all p ∈[1, ∞)
- p. 112 Appendix D, Isotonic Regression
Isotonic regression for all p ∈ [1, ∞)
Only the authors can say what is right here.
Judge's note: I checked p.5, p.83 and p.112. In Section 1.1 and Theorem 10.15 the range includes ∞. In Appendix D, the sentence stating the paper's own result excludes ∞. The authors need to say whether p = ∞ is covered. One reviewer's 'mismatched brackets' point is wrong: [1, ∞) is standard half-open interval notation, not a typo.
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Wording Section 1.1 says "p-norm flow problems and p-norm isotonic regression for all p ∈ [1, ∞]", while the supporting Theorem 10.14 for p-norm flows covers only "the sum of Õ(1) p-norm terms ... pi ≤ Õ(1)".
- p. 5 Section 1.1
as well as p-norm flow problems and p-norm isotonic regression for all p ∈[1, ∞]
- p. 82 Theorem 10.14
the sum of eO(1) p-norm terms
Only the authors can say what is right here.
Judge's note: I checked p.5 and Theorem 10.14 on p.82. Theorem 10.14 requires p_i ≤ Õ(1), which excludes p = ∞ and very large p. As written, the range [1, ∞] in Section 1.1 can be read as applying to p-norm flows as well as to isotonic regression. That is broader than the theorem states. The authors should make the scope of the range clear.
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Wording Section 1.1 gives "m^{1+o(1)} log U log C time algorithms" for generalizations including worker assignment, while Appendix D says "the worker assignment problem can be solved in time m^{1+o(1)} log^2 U in bipartite graphs".
- p. 5 Section 1.1
m1+o(1) log U log C time algorithms
- p. 110 Appendix D
can be solved in time m1+o(1) log2 U in bipartite graphs
Only the authors can say what is right here.
Judge's note: I checked p.5 and p.110. The same application gets two different bounds. Appendix D introduces no assumption that costs are bounded by U, which would explain log^2 U. Only the authors can say which bound is intended. The Appendix D sentence also has a duplicated word, 'that the the worker assignment'.
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Wording Informal Theorem 1.6 (citing Theorem 5.1) says the spanner handles "edge updates (insertions/deletions/vertex splits)", but Theorem 5.1 covers "update batches ... consisting only of edge deletions and Õ(n) vertex splits".
- p. 7 Informal Theorem 1.6
undergoing edge updates (inser- tions/deletions/vertex splits)
- p. 34 Theorem 5.1
consisting only of edge deletions and eO(n) vertex splits
- p. 7 Informal Theorem 1.6
tions/deletions/vertex splits), maintains a subgraph H
Only the authors can say what is right here.
Judge's note: I checked p.7 and p.34. Section 7 (text layer, around line 4166) says explicitly: 'we cannot simply maintain the spanner ... using Theorem 5.1 which does not support edge insertions'. It handles insertions separately by inserting them naively into the spanner. So the informal statement claims more than the cited theorem gives, though the overall construction does support insertions.
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Wording The width/upper bound w is given as "w(f) = 100 · 1 + |L(f)∆(f)|" (Sec 2.5) and as "w(t) = 10 + |ℓ(f(t)) ◦ c(t)|" (Sec 6, which says 'This is formalized in Lemma 9.2'), but Lemma 9.2 defines "w(t) = 50 + |ℓ(t) ◦ c(t)|".
- p. 17 Section 2.5
w(f) = 100 · 1 + |L(f)∆(f)|
- p. 44 Section 6, after Definition 6.1
w(t) = 10 + |ℓ(f (t)) ◦c(t)|
- p. 73 Lemma 9.2
w(t) = 50 + |ℓ(t) ◦c(t)|
Only the authors can say what is right here.
Judge's note: I checked pages 17, 44 and 73. Section 6 explicitly points to Lemma 9.2 yet uses a different additive constant. Lemma 9.2's stability step uses ε ≤ (1/100)|w|, which relies on its own constant. Section 10 (p.82) also uses 50. The constant is not essential to the argument, but the stated definitions disagree. One value should be used throughout, or the difference should be explained.
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Wording Overview (p.18) says "Because each recomputation reduces the ℓ1 norm of the width by a constant factor", but the sentence before it triggers recomputation only when ‖w(f+Δ)‖1 ≥ 100‖w(f)‖1, which is an increase.
- p. 18 Section 2.5, paragraph after Eq. (6)
Because each recomputation reduces the ℓ1 norm of the width by a constant factor, and all the widths are bounded by exp(logO(1) m)
- p. 18 Section 2.5, paragraph after (6)
Because each recomputation reduces the ℓ1 norm of the width by a constant factor
Judge's note: Checked the crop and p.18. The trigger condition in the previous sentence is a 100-fold increase of the width. The bound on the number of recomputations uses the upper cap exp(log^{O(1)} m) on the widths, and that cap only gives Õ(1) recomputations if the norm grows by a constant factor each time. "Reduces" contradicts this. The passage is in the informal overview, and the evident fix is "increases", so this is a wording error rather than a substantive one.
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Wording Proof of Lemma 4.5: in the chain "… + ½ max φ''(y)Δ²_e ≤ φ(f_e) + φ'(f_e)Δ_e + 1.3φ''(f_e)Δ²_e ≤ φ(f_e) + φ'(f_e)Δ_e + α((u⁺_e−f_e)^{−2−α} + (f_e−u⁻_e)^{−2−α})Δ²_e" the factor ½ has been dropped, so the second inequality is false as printed.
- p. 29 Proof of Lemma 4.5, Taylor bound
≤φ(fe) + φ′(fe)∆e + 1.3φ′′(fe)∆2
- p. 29 Proof of Lemma 4.5, Taylor chain
φ(fe) + φ′(fe)∆e + 1.3φ′′(fe)∆2
- p. 29 Proof of Lemma 4.5
≤ φ(fe) + φ′(fe)∆e + 1.3φ′′(fe)∆2 e
Only the authors can say what is right here.
Judge's note: Checked on page image p029. The paper gives φ''(x) = α(1+α)((u⁺−x)^{−2−α} + (x−u⁻)^{−2−α}). The middle term 1.3φ''(f_e)Δ² therefore equals 1.3α(1+α)(…)Δ², which is strictly larger than α(…)Δ² whenever Δ_e ≠ 0, so the second '≤' fails. If the ½ is kept, ½·1.3·α(1+α) = 0.65α(1+α) ≤ α for small α, so (13) still holds. The step is wrong but the stated result stands.
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Wording Proof of Lemma 4.4 bounds a nonnegative quantity by a negative one, "|g(f)⊤Δ − g̃⊤Δ| ≤ … ≤ 2ε/κ·|g̃⊤Δ| ≤ g̃⊤Δ/2", and justifies it with "ε ≤ κ/8", although ε never appears in Lemma 4.4.
- p. 29 Proof of Lemma 4.4, first display
≤2ε/κ · |eg⊤∆| ≤eg⊤∆/2,
- p. 30 Proof of Lemma 4.4
the final inequality follows from ε ≤κ/8
Only the authors can say what is right here.
Judge's note: Checked p029 to p030 and the statement of Lemma 4.4 on p028. The lemma's hypothesis is ‖L(f)^{-1}(g̃−g(f))‖∞ ≤ κ/8 and it has no ε. Since g̃⊤Δ ≤ −κ‖L̃Δ‖₁ < 0, the right-hand side g̃⊤Δ/2 is negative and cannot bound an absolute value; the intended bound is |g̃⊤Δ|/2. With ε = κ/8 the chain gives (1/4)|g̃⊤Δ| ≤ |g̃⊤Δ|/2, and (17) follows from that, so the lemma stands.
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Wording Proof of Lemma 4.4: "(c⊤f−F*)/(20m) · 4η/κ|g̃⊤Δ| ≤ κ/(500m)(c⊤f−F*)". With η|g̃⊤Δ| = κ²/50 the left side equals κ/(250m)(c⊤f−F*), not κ/(500m).
- p. 30 Proof of Lemma 4.4, bound on |c⊤Δ̄|
20m · 4η/κ|eg⊤∆| ≤ κ 500m
- p. 30 Display after (20)
· 4η/κ|eg⊤∆| ≤
Only the authors can say what is right here.
Judge's note: Checked p030 and Lemma 4.4 on p028, which chooses η with ηg̃⊤Δ = −κ²/50. Then (1/(20m))·(4/κ)·(κ²/50) = κ/(250m), so the printed κ/(500m) is half of what the displayed steps give. The κ/(500m) then feeds the term 20m(κ/500m)². Redoing it with κ/(250m) gives a term κ²/(3125m), and the final ≤ −κ²/500 still holds, so the lemma is unaffected.
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Wording Proof of Lemma 4.9: "|f_e − f̄_e| ≤ ε(u⁺_e − f_e)^{1+α} = ε(u⁺_e − f_e)(2U)^α". The equality should be ≤, since (u⁺_e − f_e)^α ≤ (2U)^α.
- p. 32 Proof of Lemma 4.9
e −fe)1+α = ε(u+
- p. 32
(0, 1/2], and
Only the authors can say what is right here.
Judge's note: Checked p032. Because 0 < u⁺−f ≤ 2U, (u⁺−f)^{1+α} = (u⁺−f)(u⁺−f)^α ≤ (u⁺−f)(2U)^α, with equality only when u⁺−f = 2U. The chain holds with ≤, so the lemma stands. The other note in this cluster, about the 'mismatched brackets' in "(0, 1/2]", is not a defect: it is standard half-open interval notation.
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Wording Theorem 5.3 gives Π₀ "vertex-congestion at most 2γcΔmax(G)", but the base case of Claim 5.7 says Π₀ "has vertex-congestion at most γcΔmax(G) by Theorem 5.3".
- p. 35 Theorem 5.3
an embedding Π0 of vertex-congestion at most 2γc∆max(G)
- p. 38 Proof of Claim 5.7, base case
has vertex-congestion at most γc∆max(G) by Theorem 5.3
- p. 35 Theorem 5.3
vertex-congestion at most 2γc∆max(G)
- p. 35
embedding Π0 of vertex-congestion at most 2γc∆max(G)
Only the authors can say what is right here.
Judge's note: Checked p035 (Theorem 5.3) and p038 (proof of Claim 5.7). The claimed base bound 4^0γc^1Δmax = γcΔmax is half of what Theorem 5.3 delivers. The factor 2 can be absorbed, since γc = exp(O(·)), so the asymptotic results stand. Only the authors can say which constant is intended.
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Wording Proof of Lemma 5.9 says the map "maps edges to paths of length γ_c^{O(L)} in H by Claim 5.8", but Claim 5.8 bounds length(Π≤i) ≤ 2^i γ_l^{i+1}, which is in terms of γ_l and not γ_c.
- p. 40 Proof of Lemma 5.9
maps edges to paths of length γO(L) c in H by Claim 5.8.
- p. 40 end of proof of Lemma 5.9
paths of length γO(L) c in H by Claim 5.8
- p. 40 Proof of Lemma 5.9, D(t) bound
maps edges to paths of length
Only the authors can say what is right here.
Judge's note: Checked p.40 (top) and Claim 5.8 on p.39. Claim 5.8 states length(Π^{(t)}_{≤i}) ≤ 2^i γ_l^{i+1}. Its bound is in terms of γ_l, while γ_c is the congestion parameter. So the cited claim gives γ_l^{O(L)}, not γ_c^{O(L)}. Lemma 5.9 states its bound as (γ_cγ_l)^{O(L)}, so the stated result still holds. The symbol in this step does not match the claim it cites.
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Wording Algorithm 5 line 18 triggers Rebuild(i,t) when updates to a level-i graph exceed "m(γs/k)^{i+1}/log^2 n", whereas the runtime proof says "the rebuild happens at most every m(γs/k)^{i0}/log^2 n total updates to graphs at level i0"; the two thresholds differ by a factor γs/k.
- p. 59 Algorithm 5, line 18
m(γs/k)i+1/ log2 n then
- p. 59 Proof of Lemma 7.9, runtime
However, the rebuild happens at most every m(γs/k)i0/ log2 n total updates to graphs at level i0.
Only the authors can say what is right here.
Judge's note: Both statements are on page 59. Because γs/k < 1, the algorithm's threshold is smaller than the one used in the amortization, so rebuilds can happen more often than the analysis assumes. Only the authors can say which threshold is intended (or how it relates to Lemma 7.8's m/(k log^2 n) limit). Whether the final m^{o(1)} bound is affected is not assessed.
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Wording "Any such counter is reset during a WIN at some level i < j" should be i ≤ j: Algorithm 6 Line 8 resets fix_j for j = i,…,d, the outline on the same page says "a WIN at some level i ≤ j", and the following sum runs from j = i.
- p. 70
Any such counter is reset during a WIN at some level i < j.
Judge's note: Page 70 image: the outline paragraph says i ≤ j, and the displayed sum Σ_{j=i}^d includes j = i. Page 65 Line 8 resets fix_j for j ≥ i. The strict inequality is inconsistent with these.
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Wording The phase-ending rule is stated two ways: 'until 1⊤y ≤ F∗ + 50νm/t. Once this holds, we will double the value of t' (p.75) and 'check whether 1⊤y(f) − F∗ ≤ 20m/t. If so, we double t' (proof of Theorem 10.13, p.78).
- p. 78 Text after Lemma 10.8
until 1⊤y ≤F ∗+ 50νm/t. Once this holds, we will double the value of t
- p. 81 Proof of Theorem 10.13
whether 1⊤y(f) −F ∗≤20m/t. If so, we double t
- p. 78 Section 10.1, before the gradient/length definitions
until 1⊤y ≤F ∗+ 50νm/t
- p. 81 Proof of Theorem 10.13
check whether 1⊤y(f) −F ∗≤20m/t
Only the authors can say what is right here.
Judge's note: Both thresholds appear as quoted on the PDF pp.78 and 81 images. Lemma 10.10 assumes a gap of at least 10m/t, and the potential-increase argument 'Z2t(f) ≤ 20m + Zt(f)' uses 20m/t. The paper does not reconcile the 50νm/t of the overview with the 20m/t of the formal proof, and ν ≥ 1. Both thresholds are O(m/t) for constant ν, so this is a consistency question for the authors.
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Wording The proof of Theorem 10.13 defines 'w def= 50+∥ℓ(f)◦c∥1', a scalar. Lemma 9.2, whose analysis the proof says it repeats, uses the per-edge vector w = 50 + |ℓ ◦ c|.
- p. 82 Proof of Theorem 10.13
w def = 50+∥ℓ(f)◦c∥1
Judge's note: Checked on the PDF p.82 image. Lemma 9.2 (text line 5779) defines w(t) = 50 + |ℓ(t) ◦ c(t)| and checks the coordinate-wise width condition of Definition 6.1. The proof of Theorem 10.13 claims 'an identical analysis to Lemma 9.2' but prints an ℓ1 norm. The evident intent is the entrywise absolute value.
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Wording Proof of Lemma 4.12 (B.1) sets f_e^(init) = (u_e^- + u_e^+)/2 and bounds each barrier term by (1/2)^{-α}, "where (i) used ... that u_e^+ − f_e^(init), f_e^(init) − u_e^- are all half-integral". This does not cover edges with u_e^- = u_e^+, which the lemma allows.
- p. 96 Proof of Lemma 4.12, bound on Φ(f^(init))
e are all half-integral.
Only the authors can say what is right here.
Judge's note: Lemma 4.12 and eq. (8) allow integral u^-, u^+ in {−U,…,U} with u^- ≤ u^+; I found no statement requiring strict inequality. The potential (9) contains (u_e^+ − f_e)^{-α} + (f_e − u_e^-)^{-α}. My counterexample: if u_e^- = u_e^+ = 3, then f_e = 3 and both residuals are 0. Zero is half-integral, so the step 'half-integral ⇒ ≥ 1/2' fails, the terms are 0^{-α} = ∞, and Φ(f^(init)) ≤ 200m log mU fails for the construction as printed. The lemma is an existence claim, and fixing such edges by moving their flow into the demands restores it, so I treat this as a proof step that needs fixing (S3), not a false result.
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Wording Proof of Lemma 6.6 (B.4) sets "t = 10kW log^2 n" after establishing max_e str̃_e ≤ kW log^2 n, but later writes "the bound str̃^i_e ≤ kW = 0.1t". The equality kW = 0.1t is false as printed, since 0.1t = kW log^2 n.
- p. 102 Appendix B.4
bound f stri e ≤kW = 0.1t
- p. 101 Appendix B.4
Let t = 10kW log2 n = eO(k).
- p. 101 Proof of Lemma 6.6
f stre ≤kW log2 n. Let t = 10kW log2 n
- p. 102 MWU bound
f stri e ≤kW = 0.1t
Only the authors can say what is right here.
Judge's note: Page images p101 and p102 match the quotes. My reworking: 0.1·t = 0.1·10kW log^2 n = kW log^2 n, which is not kW. The bound actually available is str̃ ≤ kW log^2 n = 0.1t. That still gives str̃/t ≤ 0.1, which is what the step e^x ≤ 1+2x needs, so Lemma 6.6 is unaffected. A log^2 n factor appears to have been dropped.
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Wording Lemma C.9 refers to "an instance ... of (58)" but gives "capacities u ∈ {−U, . . . , U}" (signed, no ^E). Problem (58) and T_MCC use u ∈ {1, . . . , U}^E.
- p. 105 Lemma C.9
and capacities u ∈{−U, . . . , U}, computes an optimal
- p. 105 Lemma C.9 statement
capacities u ∈{−U, . . . , U}
- p. 102 definition of (58)
capacity u ∈{1, . . . , U}E
- p. 103 Definition of TMCC
capacities u ∈{1, . . . , U}E
Judge's note: p102 (page 99) defines (58) with u ∈ {1,…,U}^E. p105 (page 102) shows Lemma C.9 with {−U,…,U} and no edge index. This looks like a notation slip with an evident fix ({1,…,U}^E); negative capacities have no meaning in (58), where 0 ≤ f_e ≤ u_e.
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Wording Lemma C.10 states the runtime as "O(T_A(m) log m log U + m log m log U)" and Algorithm 10 sets "T ← O(log U)". The same lemma's 'In other word' clause and the proof's conclusion use log mU ("After T = O(log m + log U) = O(log mU) iterations"; "Overall, the runtime is O(T_A(m) log m log mU + m log m log mU)").
- p. 106 Lemma C.10 statement
O(TA(m) log m log U + m log m log U)-time
- p. 109 end of proof of Lemma C.10
Overall, the runtime is O(TA(m) log m log mU + m log m log mU)
Only the authors can say what is right here.
Judge's note: p106 (page 103) shows the lemma with log U and the clause with log mU. p109 (page 106) shows Algorithm 10 with T ← O(log U) and the proof deriving O(log mU) iterations. The two forms agree only when log m = O(log U); the authors should say which is intended.
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Wording Lemma C.14 says f^B "is an integral 1.1-approximate solution", but the proof of Lemma C.10 says "Lemma C.14 states that the augmenting circulation ∆f is always a 2-approximation".
- p. 107 Lemma C.14 statement
f B is an integral 1.1-approximate solution
- p. 109 proof of Lemma C.10
Lemma C.14 states that the augmenting circulation ∆f is always a 2-approximation
- p. 107 Lemma C.14 statement
is an integral 1.1-approximate solution for the original
- p. 107
f B is an integral 1.1-approximate solution for the original
Judge's note: Checked p.107 and p.109. A 1.1-approximation is also a 2-approximation, so the argument is valid. Only the wording 'states ... 2-approximation' misquotes the lemma. Its proof actually gives a (1−2m^−8) factor.
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Wording Algorithm 10, line 3 sets "T ← O(log U)", but the proof of Lemma C.10 needs "T = O(log m + log U) = O(log mU) iterations".
- p. 109 Algorithm 10, line 3
T ←O(log U)
- p. 109 Proof of Lemma C.10
After T = O(log m + log U) = O(log mU) iterations
Judge's note: Checked p.109 and the statement of Lemma C.10 in the text layer (runtime 'O(T_A(m) log m log U + ...)', and 'log m log mU' in the next sentence). The proof needs m^11·U/2^T ≤ 1/2, i.e. T ≥ log2(2m^11·U). When U is small relative to m, O(log U) iterations do not meet this. The algorithm line and part of the lemma statement should read O(log mU).
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Wording "an algorithm that runs in near-linear time to compute p-norm flows": the result it relies on (Theorem 10.14) gives m^{1+o(1)} time, which the paper elsewhere calls almost-linear.
- p. 110 Appendix D
runs in near-linear time to compute p-norm flows
Judge's note: Checked p.110. Theorem 10.14 in the text layer states 'in m^{1+o(1)} time'. The paper uses 'almost-linear' for m^{1+o(1)} and uses 'nearly-linear' for Õ(m) results (e.g. [ST04]), so this wording is inconsistent.
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Wording The SSSP reduction sets "d_s = n and d_v = −1 for all v ∈ V". This assigns s two demands. Reading it as v ≠ s, the demands sum to n − (n−1) = 1 rather than 0, so the instance is infeasible. Presumably d_s = n − 1 was intended.
- p. 111 Appendix D, Negative Shortest-Paths
ds = n and dv = −1 for all v ∈V
Judge's note: Checked p.111. Flow demands must sum to zero. Example with n = 10: 10 − 9 = 1 ≠ 0. This is an informal sketch with an evident fix.
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Typo Below Eq. (2): "for demands d ∈ R^E". Demands are vertex quantities (B^T f = d with B ∈ R^{E×V}; Section 1 states d ∈ R^V), so this should read d ∈ R^V.
- p. 9 Section 2.1, text after Eq. (2)
for demands d ∈RE, lower and upper capacities
- p. 4 Section 1, problem definition
vertex demands d ∈RV
- p. 9 Section 2.1, below eq. (2)
for demands d ∈RE
Judge's note: The page image of p.9 shows R^E for d. Section 1 (p.4) and Section 3 ('routes a demand d ∈ R^V') define demands on vertices. The intended meaning is clear from context, so this is a notation slip.
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Typo Appendix A.1 prints the Goldberg–Rao bound as "O(m min(√m, n^{2/3} log U) for max-flow": two parentheses are opened but only one is closed. The introduction gives the bound as Õ(m min{m^{1/2}, n^{2/3}} log U).
- p. 94 Appendix A.1
O(m min(√m, n2/3 log U) for max-flow
- p. 94 Appendix A.1
O(m min(√m, n2/3 log U) for
- p. 4 Introduction
eO(m min{m1/2, n2/3} log U)
Judge's note: The p94 crop shows the unbalanced parentheses. The introduction (text near line 237, p4) puts log U outside the min. Because of the missing parenthesis, the appendix leaves unclear whether log U multiplies the whole bound. The fix is evident: close the min before log U.
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Typo Duplicated article: "than those required in the the recent works on robust interior point methods" (p.3, PDF p.6).
- p. 6 Section 1.2
required in the the recent works on robust interior point methods
- p. 6 Section 1.2
required in the the recent works
- p. 6
than those required in the the recent works on robust interior point methods
- p. 6
actors than those required in the the recent works on rob
Judge's note: The page image of p.6 shows 'the the'.
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Typo Grammar: "the set of edges that are embed into a fixed edge e ∈ H" (should be 'embedded') and "are utilized to efficiently implementing the ℓ1 IPM algorithm" (should be 'implement') on p.4 (PDF p.7).
- p. 7 Informal Theorem 1.6
the set of edges that are embed into a fixed edge e ∈H
- p. 7 Informal Theorem 1.6
the set of edges that are embed into a fixed edge
- p. 7 after Informal Thm 1.5
are utilized to efficiently implementing the ℓ1 IPM algorithm
Judge's note: Both slips are visible on the page image of p.7.
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Typo Garbled word order: "we are able to argue that a solving sequence of Õ(m) ℓ1 minimizing subproblems ... suffice" (should be 'solving a sequence of').
- p. 9 Section 2.1
able to argue that a solving sequence of
- p. 9 Sec 2.1
able to argue that a solving sequence of eO(m) ℓ1 minimizing subproblems
Judge's note: Visible on the page image of p.9.
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Typo Misspelling: "forcing both its endpoints to become root notes" should be 'root nodes' (p.11, PDF p.14).
- p. 14 Section 2.3
forcing both its endpoints to become root notes
- p. 14 Forest Routings paragraph
both its endpoints to become root notes
Judge's note: Visible on the page image of p.14. The previous sentence uses 'root nodes'.
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Typo Misspelling on p.20, Sec. 2.7 item 3: "we maintain the spannner such that".
- p. 20 Section 2.7, item 3
we maintain the spannner
- p. 20 Sec 2.7 item 3
we maintain the spannner such that
- p. 20
we maintain the spannner such that for every edge
Judge's note: The crop shows "spannner" with three n's.
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Typo Garbled sentence on p.20, end of Sec. 2.6: "a data structure that handles successfully finds update cycles".
- p. 20 Sec 2.6 last paragraph
a data structure that handles successfully finds update cycles
- p. 20
data structure that handles successfully finds
Judge's note: The crop shows the sentence as quoted. It has two verbs, so one of them ("handles") should go.
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Typo Expander definition on p.21: "E_{H_i}(X, X̄) is the set of edges in H_i with endpoints in X and S̄". It should say X and X̄.
- p. 21 Section 2.7, A Static Algorithm
is the set of edges in Hi with endpoints in X and S
- p. 21 Section 2.7, A Static Algorithm
with endpoints in X and S
- p. 21
with endpoints in X and S and volHi(Y )
Judge's note: The crop shows "X and S̄" (S with an overbar). The cut has just been defined as (X, X̄) with X̄ = V(H_i) \ X, and S is not defined at this point. The symbol is a slip.
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Typo Duplicated word on p.22: "the maximum length of the the embedding paths".
- p. 22 Section 2.7, Dynamic Algorithm
the maximum length of the the embedding paths
- p. 22
edges), the maximum length of the the embedding paths has
Judge's note: The crop shows "the the".
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Typo Preliminaries, p.24: "We let Δmax(G) and Δmin(G) denote the maximum and minimum degree of graph H." The graph should be G.
- p. 24 Section 3, Graphs
and ∆min(G) denote the maximum and minimum degree of graph H.
- p. 24 Graphs paragraph
the maximum and minimum degree of graph H
- p. 24 Section 3, Graphs
minimum degree of graph H
- p. 24
denote the maximum and minimum degree of graph H
Judge's note: The crop and p.24 show the sentence as quoted. The notation is defined for G.
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Typo Two copy-edit slips on p.25: "Π_{G→H} is an graph-embedding", and the sentence "Enc(u) of an update u ∈ U(t) be the size of the encoding..." has no opening "We let".
- p. 25 Section 3, Graph Embeddings
is an graph-embedding from G into H
- p. 25 Section 3, Dynamic Graphs
Enc(u) of an update u ∈U(t) be the size of the encoding
Judge's note: The full-page image of PDF p.25 (printed page 22) shows both as quoted.
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Typo Duplicated word in Lemma 3.3 item 4 (p.26): "Δ = p(T[u,v]), or or query the value f_e".
- p. 26 Lemma 3.3, item 4
or or query the value fe
- p. 26 Lemma 3.3 item 4
or or query the value fe in amortized time
Judge's note: The crop shows "or or".
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Typo Lemma 4.7 hypothesis reads "‖L(g)^{-1}(g̃ − g(f))‖∞ ≤ ε"; L(g) is undefined and L(f) is meant.
- p. 31 Lemma 4.7 statement
Let eg ∈RE satisfy L(g)−1 (eg −g(f))
- p. 31 Lemma 4.7 hypothesis
L(g)−1 (eg −g(f))
- p. 31 proof
g(f)⊤(f ∗−g)
Judge's note: Page image p031 shows L(g)^{-1} in the statement of Lemma 4.7. L = diag(ℓ(f)) is a function of the flow; Lemma 4.4, Lemma 4.8 and the proof of 4.7 itself all use L(f)^{-1}. The (f*−g) typo, which some notes in this cluster also raise, is judged in C037.
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Typo Proof of Lemma 4.7: "g̃⊤(f*−f) = g(f)⊤(f*−g) + (g̃−g(f))⊤(f*−f)" should read g(f)⊤(f*−f).
- p. 31 Proof of Lemma 4.7
eg⊤(f ∗−f) = g(f)⊤(f ∗−g) + (eg −g(f))⊤(f ∗−f)
- p. 31 Proof of Lemma 4.7, line starting g̃ᵀ(f*−f) =
g(f)⊤(f ∗−g) + (eg −g(f))⊤(f ∗−f)
Judge's note: Page image p031 shows (f*−g). The decomposition only holds with f*−f in both terms, and g is a gradient, not a flow.
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Typo Proof of Lemma 4.7: "(ii) follows from the the conditions on g̃" has a duplicated "the".
- p. 31 Proof of Lemma 4.7, (ii)
follows from the the conditions on
- p. 31
∞norms, and (ii) follows from the the conditions on eg. T
Judge's note: The doubled word is visible on page image p031.
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Typo Lemma 4.12: "costs and lower/upper capacities c, u⁻, u⁺ ∈ {−U, …, U}^V" should be indexed by E.
- p. 34 Lemma 4.12 statement
capacities c, u−, u+ ∈{−U, . . . , U}V
- p. 34 Lemma 4.12
c, u−, u+ ∈{−U, . . . , U}V
Judge's note: Page image p034. Costs and capacities are edge vectors, and the output instance in the same lemma is typed correctly as {…}^{E(G̃)}. Only the demands d are indexed by V.
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Typo Theorem 5.1 item 3: "Σ_{t′≤t} |D^{(t′)}| = Õ(Σ_{t′≤t} |U^{(t)}| · n^{1/L}(γcγl)^{O(L)})". The summand should be |U^{(t′)}|.
- p. 34 Theorem 5.1, item 3
we have P t′≤t |D(t′)| = eO P t′≤t |U(t)| · n1/L(γcγl)O(L)
Judge's note: Page image p034 shows U^{(t)} inside a sum over t′. Item 1 of the same theorem writes |U^{(t′)}|.
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Typo Misspelling "Recall the definiton of expanders." (should be "definition").
- p. 40 Sec 5.2
Recall the definiton of expanders.
Judge's note: Seen on the p.40 page image, just above Definition 5.10.
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Typo Algorithm 2 line 9 reads "while there exists an edge e ∈ E(J[X_i])", whereas everywhere else the graph is J_i[X].
- p. 41 Algorithm 2, line 9
while there exists an edge e ∈E(J[Xi]) with
Judge's note: p.41 image: lines 5, 6 and the comment use J_i[X], and the proof of Claim 5.15 (p.43) uses E(J_i[X]). X_i is never defined, so the index is misplaced.
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Typo Claim 5.16 states "with probability at least 1 − n^{−2c}" with a lowercase c, while the failure-probability constant is C everywhere else.
- p. 43 Claim 5.16
with probability at least 1 −n−2c.
- p. 43 Claim 5.16
with probability at least 1 −n−2c
- p. 43 Claim 5.16
with probability at least
Judge's note: p.43 image: the claim prints n^{-2c}, but its own proof gives 1−2n^{-4C}. Theorem 5.5 uses n^{-C}, and no lowercase constant c is defined for this purpose.
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Typo Doubled word in proof of Claim 5.15: "loop starting in Line 9 by by O(log(m))".
- p. 43 Proof of Claim 5.15
loop starting in Line 9 by by O(log(m))
- p. 43 Proof of Claim 5.15
that where not embedded before
- p. 43 Proof of Claim 5.15
starting in Line 9 by by O(log(m))
- p. 43
while loop starting in Line 9 by by O(log(m)). We can t
Judge's note: Seen on the p.43 page image. The 'where'/'were' typo in the same proof is handled under C052.
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Typo Proof of Claim 5.15: "that where not embedded before" (were) and "as the algorithm track congestion" (tracks).
- p. 43 Proof of Claim 5.15
that where not embedded before the current while-loop iteration
- p. 43 same proof
as the algorithm track congestion
Judge's note: Both are seen on the p.43 page image.
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Typo Lemma 6.5 item 1: "q := Σ_{t=1}^{τ} Enc(U^{(i)})" — the summation index is t but the summand is indexed by i.
- p. 46 Lemma 6.5, item 1
q def = Pτ t=1 Enc(U(i))
Judge's note: p.46 image confirms the sum over t=1..τ with summand Enc(U^{(i)}). The summand should be U^{(t)}.
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Typo Grammar: "we show Theorem 7.1, we gives a data structure" (p.49) and "Definition 6.7 indeed given the correct total gradient" (p.61, should be "give").
- p. 49 end of Sec 6.4
we gives a data structure whose guarantee is weaker
- p. 61 before Lemma 7.13
indeed given the correct total gradient
Judge's note: Both phrases are seen on the p.49 page image and the p.61 crop.
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Typo Definition 7.3: "with a tree T, arooted spanning forest" — missing space ("a rooted").
- p. 50 Def 7.3
with a tree T, arooted spanning forest
Judge's note: The p.50 page image shows 'arooted' with no space, so this is not an extraction artefact.
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Typo Proof of Lemma 7.5 prints the expectation as "Σ_{i=j}^{t} λ_j str~^j_e" (index i, summand in j), and concludes "there exists an i* satisfying (26)" while the statement (Item 2) names "an j* ∈ [B]".
- p. 52 Proof of Lemma 7.5, expectation display
t X i=j λj f strj e
- p. 52 Proof of Lemma 7.5, end
we get that there exists an i∗satisfying (26)
- p. 51 Lemma 7.5 item 2
there is an j∗∈[B] only depending on w(0)
- p. 52 end of proof
there exists an i∗satisfying
Judge's note: I checked the p.52 image (expectation display and last paragraph) and the p.51 image (Lemma 7.5 Item 2, which uses j* and F_{j*} in (26)). The sum should run over i=1..t with λ_i and the i-th tree's stretch. The witness index is renamed from j* to i*. Both are index typos.
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Typo Algorithm 5 caption: "Rebuild rebuilds the data structure of level at least d_s at stage t0"; the symbol d_s is undefined, and the procedure Rebuild(i0, t0) rebuilds levels i ≥ i0.
- p. 59 Algorithm 5 caption
rebuilds the data structure of level at least ds at stage t0
Judge's note: Page 59 image: lines 8–9 of the algorithm show Rebuild(i0,t0) looping over i = i0,…,d−1. 'd_s' is not defined in this context; it should be i0.
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Typo Duplicated article: "by induction on t and the the level i".
- p. 59 Proof of Lemma 7.9
induction on t and the the level i
- p. 59
ow (32) by induction on t and the the level i, and prove
Judge's note: Visible on the page 59 image, bottom paragraph.
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Typo Proof of Theorem 7.1 sets "γs = γr = exp(log^{3/4} log log m)", which drops the 'm' (and the O(·)) from exp(O(log^{3/4} m log log m)) as used in Lemma 7.8.
- p. 64 Proof of Theorem 7.1
γs = γr = exp(log3/4 log log m)
- p. 64
e choice γs = γr = exp(log3/4 log log m), d = log1/8 m an
Judge's note: Page 64 image confirms the printed formula has no 'm' after log^{3/4}. Lemma 7.8 (p.54) gives exp(O(log^{3/4} m log log m)). The repeated 'log' itself is the legitimate iterated logarithm.
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Typo Section 8 copy-editing errors: "When is this does not happen", "integers parameters size m > 0", "an ad-vesary", "At the beginning each round".
- p. 64 Section 8 intro
When is this does not happen
- p. 64 Definition 8.1
ad- vesary
- p. 64 Def 8.1
played between a player and an ad- vesary
- p. 64 Rebuilding game parameters
integers parameters size m > 0
Judge's note: All four phrases are visible on the page 64 image.
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Typo Page 66 typos: "thus rebuiling levels j ≥ i", "a fixing step occured", "outline the main the main elements".
- p. 66 Section 8, rebuilding game algorithm
thus rebuiling levels j ≥i
- p. 66 Section 8.1
outline the main the main elements
Judge's note: All three are visible on the page 66 image.
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Typo Copy-edit slips in Section 8: "thus rebuiling levels" and "a fixing step occured" (p.66), "This lemma tells use that" (p.67), "the cost form LOSSes" and "the level i experienced least γgm/k^i rounds" (p.70), and "this means the cost amortized to toward a round across all levels is ." (p.71).
- p. 71 Proof of Lemma 8.3
amortized to toward a round across all levels is .
- p. 66 Sec 8 algorithm description
(thus rebuiling levels j ≥i)
- p. 66 same
a fixing step occured
- p. 67 after Lemma 8.5
This lemma tells use that
Judge's note: Every quoted slip is visible in the page images and crops: rebuiling→rebuilding, occured→occurred, use→us, form→from, missing 'at', and 'amortized to toward … is .', which is garbled and ends in a dangling period before eq. (43).
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Typo Lemma 10.7 opens 'Let f : X → R be a convex function on an open set X ⊆ R2' but then uses ψ throughout ('y(x) = argmin_y ψ(x,y)', 'ζ(x) = ψ(x,y(x))'), and mixes f_x, f_y with ψ_x, ψ_y ('= f_x(x, y(x))', 'recall that f_y(x,y(x)) = 0'). There are also typos: 'Each phase will requires' (p.75) and 'a good quality circlation ∆' (p.78).
- p. 77 Lemma 10.7
Let f : X →R be a convex function on an open set X ⊆R2.
- p. 77 Eq. (48)
ζ′(x) = ⟨∇ψ(x, y(x)), v⟩= fx(x, y(x)),
- p. 78 before (52)
Each phase will requires approximately
- p. 81 before Lemma 10.12
a good quality circlation ∆
Judge's note: Checked on the page images of PDF pp.77, 78 and 81. The function is introduced as f, but the definitions of y(x) and ζ(x) and equations (49)–(51) use ψ. Equation (48) and its proof write f_x and f_y, and the proof of (51) says 'recall that f_y(x,y(x))=0' and then uses ψ_xy and ψ_yy. Bold f is also the paper's symbol for flows. The intended meaning is clear, so these are notation slips and copy-editing errors. 'requires' should be 'require' and 'circlation' should be 'circulation'.
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Typo Section 10.2 (isotonic regression) contains 'add a few vertex v∗ to the graph G' (should be 'a new vertex'), 'force f to to have 0 demand' (duplicated 'to'), and '(eg. using a logarithmic barrier)' (should be 'e.g.').
- p. 83 Section 10.2
add a few vertex v∗to the graph G
- p. 83 Section 10.2
force f to to have 0 demand
- p. 83 same paragraph
(eg. using a logarithmic barrier)
- p. 83
ic barrier). Finally, force f to to have 0 demand on th
Judge's note: Checked on the PDF p.83 image. All three typos appear as quoted. Only a single vertex v∗ is added, so 'a few' should be 'a new'.
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Typo Reference typos: the [HK73] title is typeset with raw LaTeX source ("An $n̂{5/2} $ Algorithm for Maximum Matchings…"), and [BLSS20] reads "Proccedings of the 52nd Annual…".
- p. 89 Reference [HK73]
“An $nˆ{5/2} $ Algorithm for Max- imum Matchings in Bipartite Graphs”
- p. 86 [BLSS20]
Proccedings of the 52nd Annual
- p. 89 [HK73]
An $nˆ{5/2} $ Algorithm for Max-
- p. 86
In: Proccedings of the 52nd Annual
Judge's note: The p89 crop shows the dollar signs and braces printed literally in the [HK73] title. The p86 crop shows 'Proccedings' in italics in [BLSS20]. Both are visible on the page, so neither is an extraction artefact.
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Typo Appendix A, opening paragraph: "can be found the CACM article by Goldberg and Tarjan" is missing "in".
- p. 93 App A
can be found the CACM article
Judge's note: The p93 crop shows the sentence exactly as quoted. The other typos this reviewer lists on p95 are handled under C111.
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Typo Appendix A.1, second bullet: the citation group "[CKMST11; Mąd13; LS19; Mąd16; LS19; KLS20]" lists LS19 twice.
- p. 95 Appendix A.1, second bullet
[CKMST11; Mąd13; LS19; Mąd16; LS19; KLS20]
Judge's note: The full page image p95 (printed page 92) shows LS19 twice in the same bracket. One occurrence may have been meant as a different reference; only the authors can say.
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Typo Copy-editing typos in Appendices A and D: "data structured tailored", "arbitrary integer capcities", "Many these algorithms", "the the worker assignment problem", "one can simple split", "insert and edge (v_in, v_out)", "miminizing over", "The goal is to find project y on to".
- p. 95 Appendix A
data structured tailored to electrical
- p. 95 Appendix A.2
arbitrary integer capcities
- p. 95 Appendix A.1
via data structured tailored to electrical
- p. 95 A.2
Many these algorithms
Judge's note: Each typo is visible in the page images: p95 (data structured, capcities, Many these), p110 (the the, can simple split, insert and edge), p111 (miminizing) and p112 (find project). All are cosmetic.
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Typo Typos in Appendix B.3/B.4: "potential roots that an edge e is assigned too", "v_1 := 1 is an the all 1's vector", and "Next, we upper bounds ‖v_i‖_1".
- p. 98 Proof of Lemma 6.5 (heavy-light)
roots that an edge e is assigned too
- p. 102 Proof of Lemma 6.6
v1 def = 1 is an the all 1’s vector
- p. 102 same
Next, we upper bounds ∥vi∥1
Judge's note: Seen in the crops from p98 and p102.
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Typo In the flow-diffusion reduction, the vertex capacity vector is introduced as "d ∈ R^V", but the construction then uses "for each vertex v ∈ V where b_v ≤ 0 (resp. b_v > 0), with ... upper capacity |b_v|", and b is not defined there.
- p. 110 Appendix D, Extensions of Theorem 1.1
for each vertex v ∈V where bv ≤0 (resp. bv > 0), with lower capacity 0, upper capacity |bv|
- p. 110 Appendix D, Extensions of Theorem 1.1
for each vertex v ∈V where bv ≤0 (resp. bv > 0)
- p. 110 App D, Extensions
where bv ≤0 (resp. bv > 0)
Judge's note: Checked p.110. d is defined in the preceding sentence, and b_v appears with no definition. Later on the same page, b denotes the worker-assignment degree vector, a different object. d_v is evidently what was meant.
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Typo Duplicated word: "Our result implies that the the worker assignment problem".
- p. 110 Appendix D, Bipartite Matching
the the worker assignment problem
- p. 110
Our result implies that the the worker assignment problem
- p. 110
ists. Our result implies that the the worker assignment p
Judge's note: Visible on p.110 (printed p.107).
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Typo Typos in Appendix D: "one can simple split" should be "simply", and "then insert and edge (v_in, v_out)" should be "an edge".
- p. 110 Appendix D, Extensions of Theorem 1.1
then insert and edge (vin, vout)
- p. 110 Extensions of Theorem 1.1
one can simple split
- p. 110 same
insert and edge (vin, vout)
- p. 110
then insert and edge (vin, vout) with
Judge's note: Both are visible on p.110.
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Typo "using Cut-Link Trees [ST83] on can recover a negative cycle": should read "link-cut trees" and "one can".
- p. 111 Appendix D
using Cut-Link Trees [ST83] on can recover a negative cycle
- p. 111 Appendix D
using Cut-Link Trees [ST83] on can recover
- p. 111 Appendix D, negative cycle detection
using Cut-Link Trees [ST83]
- p. 111 Appendix D, Negative Shortest-Paths
Cut-Link Trees [ST83]
Judge's note: Checked p.111. Everywhere else the paper calls the [ST83] structure 'link-cut trees' (text layer lines 214, 709, 3216). 'on' is a typo for 'one'.
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Typo Misspelling "obtained by miminizing over" (should be "minimizing"). The same sentence also repeats "time": "in time mn^{1/2+o(1)} time".
- p. 111 Appendix D, Connectivity
obtained by miminizing over
- p. 112 Isotonic regression
The goal is to find project y on to the space
Judge's note: Checked p.111. The 'find project y' part of this cluster is handled separately as C135.
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Typo Garbled phrase: "The goal is to find project y on to the space of vectors that are isotonic". It should read e.g. "to project y onto" or "to find the projection of y onto".
- p. 112 Appendix D, Isotonic Regression
The goal is to find project y
Judge's note: Visible on p.112 (printed p.109).
Second check: none (judge only)