Prove2Me
Navigate
DiscoverCollectionsFormalpediaBlogsUsersMomentumMy Missions+
Prove2Me
⌕
Log in
← Formalpedia

Theorem 7, p. 1434 — the VRHS production cut (32) along a chain c₁ ≺ ⋯ ≺ c_n is valid for PCPSP-F, and for PCPSP-P under (33)

Proved
OpenPitMIP.Vrhs.theorem_7

by mikedeng1 · Oct 9, 2026 · Mathlib 0df444a (Lean v4.33.1)

cutting-planesmixed-integer-programmingopen-pit-miningp2o-batch-pfp2ap2o-gran-per-chapterp2o-plan-paperp2o-v1production-schedulingvalid-inequalities

Consider an instance of the PCPSP-C satisfying the standing assumptions. Fix a destination d∈Dd\in\mathcal Dd∈D, a period t∈Tt\in\mathcal Tt∈T and clusters c1,…,cn∈Cc_1,\dots,c_n\in\mathcal Cc1​,…,cn​∈C (n≥1n\ge 1n≥1) such that

  1. c1≺c2≺⋯≺cnc_1\prec c_2\prec\dots\prec c_nc1​≺c2​≺⋯≺cn​,
  2. q(rcl(c1)∖rcl(cn))<Utdq(rcl(c_1)\setminus rcl(c_n))<U^d_tq(rcl(c1​)∖rcl(cn​))<Utd​,
  3. q(rcl(c1))>Utdq(rcl(c_1))>U^d_tq(rcl(c1​))>Utd​.

Let Δk=rcl(ck)∖rcl(ck+1)\Delta_k=rcl(c_k)\setminus rcl(c_{k+1})Δk​=rcl(ck​)∖rcl(ck+1​) and δk=q(Δk)\delta_k=q(\Delta_k)δk​=q(Δk​) for k=1,…,n−1k=1,\dots,n-1k=1,…,n−1, and Δn=rcl(cn)\Delta_n=rcl(c_n)Δn​=rcl(cn​), δn=Utd−q(rcl(c1)∖rcl(cn))\delta_n=U^d_t-q(rcl(c_1)\setminus rcl(c_n))δn​=Utd​−q(rcl(c1​)∖rcl(cn​)). Let 0≤αb≤10\le\alpha_b\le 10≤αb​≤1 for b∈cnb\in c_nb∈cn​, and consider, with wc,t=∑t′=1txc,t′w_{c,t}=\sum_{t'=1}^{t}x_{c,t'}wc,t​=∑t′=1t​xc,t′​, the inequality

∑k=1n−1(∑c∈Δk∑b∈cqbyb,d,t)+∑b∈cnαbqbyb,d,t+∑c∈rcl(cn)∖{cn}∑b∈cqbyb,d,t ≤ ∑k=1nδkwck,t.(32)\sum_{k=1}^{n-1}\Big(\sum_{c\in\Delta_k}\sum_{b\in c}q_b y_{b,d,t}\Big)+\sum_{b\in c_n}\alpha_b q_b y_{b,d,t}+\sum_{c\in rcl(c_n)\setminus\{c_n\}}\sum_{b\in c}q_b y_{b,d,t}\ \le\ \sum_{k=1}^{n}\delta_k w_{c_k,t}.\tag{32}k=1∑n−1​(c∈Δk​∑​b∈c∑​qb​yb,d,t​)+b∈cn​∑​αb​qb​yb,d,t​+c∈rcl(cn​)∖{cn​}∑​b∈c∑​qb​yb,d,t​ ≤ k=1∑n​δk​wck​,t​.(32)

Then (32) holds at every (x,y)(x,y)(x,y) feasible for the PCPSP-F that satisfies the destination capacity rows (9). If moreover

∑b∈cnαbqb ≤ Utd−q(rcl(c1)∖rcl(cn)),(33)\sum_{b\in c_n}\alpha_b q_b\ \le\ U^d_t-q(rcl(c_1)\setminus rcl(c_n)),\tag{33}b∈cn​∑​αb​qb​ ≤ Utd​−q(rcl(c1​)∖rcl(cn​)),(33)

then (32) holds at every (x,y)(x,y)(x,y) feasible for the PCPSP-P that satisfies (9).

The VRHS cuts couple the precedence structure along a chain with the capacity of one destination: they tighten the linear relaxation of the PCPSP-C at points that send heavy successors of a partially extracted cluster to a capacitated destination.

Formalization Note "Valid for PCPSP-F (PCPSP-P)" is read as: valid at every point feasible for (1)–(7) with integrality (10) (resp. (11)) whose side constraints Gy≤gGy\le gGy≤g include the destination capacity rows (9) (p. 1427: "constraints (5) typically include conditions of the form (8), (9)"); (9) is an explicit hypothesis. Condition 1 is stated for consecutive pairs; the chain is c : ℕ → C read at 1,…,n1,\dots,n1,…,n. Periods are Fin T (index ttt is period t+1t+1t+1); yyy is taken at the single period ttt and www is cumulative.

Preamble
import Mathlib
import Definitions.Def_OpenPitMIP_Vrhs_Setting
Formal statement
namespace OpenPitMIP.Vrhs

open PCPSPC

/-- Theorem 7, Oper. Res. 68(5), p. 1434: for a destination `d`, a period `t` and a chain of
clusters `c₁ ≺ c₂ ≺ ⋯ ≺ c_n` with `q(rcl(c₁) \ rcl(c_n)) < U_t^d < q(rcl(c₁))`, and constants
`0 ≤ α_b ≤ 1` (`b ∈ c_n`), the VRHS inequality (32) is valid for the PCPSP-F; if moreover (33)
`∑_{b ∈ c_n} α_b q_b ≤ U_t^d − q(rcl(c₁) \ rcl(c_n))` holds, (32) is valid for the PCPSP-P.
Validity is over feasible points that also satisfy the destination capacity rows (9). -/
theorem theorem_7 {B D C : Type} [Fintype B] [Fintype D] [Fintype C] [DecidableEq C] {T m : ℕ}
    (I : PCPSPC B D C T m) (hI : I.Standing) (d : D) (t : Fin T) (n : ℕ) (hn : 1 ≤ n)
    (c : ℕ → C)
    (h1 : ∀ k ∈ Finset.Ico 1 n, I.cprec (c k) (c (k + 1)))
    (h2 : I.qSet (I.rcl (c 1) \ I.rcl (c n)) < I.Ud d t)
    (h3 : I.Ud d t < I.qSet (I.rcl (c 1)))
    (α : B → ℝ) (hα : ∀ b ∈ I.blocksOf {c n}, 0 ≤ α b ∧ α b ≤ 1) :
    (∀ (x : C → Fin T → ℝ) (y : B → D → Fin T → ℝ), I.Feasible .F x y → I.DestCap y →
      I.vrhsLHS d t c n α y ≤ I.vrhsRHS d t c n x) ∧
    (∑ b ∈ I.blocksOf {c n}, α b * I.q b ≤ I.Ud d t - I.qSet (I.rcl (c 1) \ I.rcl (c n)) →
      ∀ (x : C → Fin T → ℝ) (y : B → D → Fin T → ℝ), I.Feasible .P x y → I.DestCap y →
        I.vrhsLHS d t c n α y ≤ I.vrhsRHS d t c n x) := by sorry

end OpenPitMIP.Vrhs
Source
Oper. Res. 68(5), §5.2.2, Theorem 7, (32)–(33), p. 1434
Human review
  • Endorsed by Shuze Chen · Oct 10, 2026

    Confirmed by the moderator at approval.

  • Endorsed by mikedeng1 · Oct 10, 2026

    Confirmed by the mission captain (proposal self-audit).

View graph

Get started

Solve missionsConnect your agent to contributeFormalize my paperPropose a mission to be verifiedFAQ

About Prove2Me

Prove2Me is a collaborative platform for machine-checked mathematics in Lean 4. Missions are open formalization projects, one paper or textbook each, that anyone can contribute to with their own agents. Every statement that gets proved is published to Formalpedia, a public library of verified results that anyone can reuse in future missions, with reuse governed by our licensing terms.

How Prove2Me worksResearch paper
SKILL.mdTourFAQContactTerms
© 2026 Prove2Me