pith. machine review for the scientific record. sign in
structure

Chain

definition
show as:
view math explainer →
module
IndisputableMonolith.Recognition
domain
Recognition
line
35 · github
papers citing
none yet

open explainer

Generate a durable explainer page for this declaration.

open lean source

IndisputableMonolith.Recognition on GitHub at line 35.

browse module

All declarations in this module, on Recognition.

explainer page

Tracked in the explainer inventory; generation is lazy so crawlers do not trigger LLM jobs.

open explainer

depends on

used by

formal source

  32  U : Type
  33  R : U → U → Prop
  34
  35structure Chain (M : RecognitionStructure) where
  36  n : Nat
  37  f : Fin (n+1) → M.U
  38  ok : ∀ i : Fin n, M.R (f i.castSucc) (f i.succ)
  39
  40namespace Chain
  41variable {M : RecognitionStructure} (ch : Chain M)
  42def head : M.U := by
  43  have hpos : 0 < ch.n + 1 := Nat.succ_pos _
  44  exact ch.f ⟨0, hpos⟩
  45def last : M.U := by
  46  have hlt : ch.n < ch.n + 1 := Nat.lt_succ_self _
  47  exact ch.f ⟨ch.n, hlt⟩
  48end Chain
  49
  50structure Ledger (M : RecognitionStructure) where
  51  debit : M.U → ℤ
  52  credit : M.U → ℤ
  53
  54@[simp] def Ledger.Carrier {M : RecognitionStructure} (_ : Ledger M) : Type :=
  55  M.U
  56
  57def phi {M} (L : Ledger M) : M.U → ℤ := fun u => L.debit u - L.credit u
  58
  59def chainFlux {M} (L : Ledger M) (ch : Chain M) : ℤ :=
  60  phi L (Chain.last ch) - phi L (Chain.head ch)
  61
  62class Conserves {M} (L : Ledger M) : Prop where
  63  conserve : ∀ ch : Chain M, ch.head = ch.last → chainFlux L ch = 0
  64
  65lemma chainFlux_zero_of_loop {M} (L : Ledger M) [Conserves L] (ch : Chain M) (h : ch.head = ch.last) :