HomologicalComplex.lean`

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1 declarations, 0 contain sorry, 0 declared as axioms

Complements on homological complexes

Material destined for Mathlib.Algebra.Homology.HomologicalComplex.

Imports (1)

Mathlib.Algebra.Homology.HomologicalComplex

Imported by 2 files

lemma CochainComplex.prev_nat The predecessor function of the cochain complex shape on ℕ is truncated subtraction line 19 source
Source documentation
The predecessor function of the cochain complex shape on ℕ is truncated subtraction.

standard axioms: Classical.choice, Quot.sound, propext what this means
Statement uses: Nat, Eq, ComplexShape.prev, ComplexShape.up, HSub.hSub, OfNat.ofNat
Proof uses: Nat.casesAuxOn, of_eq_true, Eq.trans, True, congr, congrArg, CochainComplex.prev_nat_zero, Nat.sub_eq_zero_of_le, LE.le, eq_self, Eq.symm, HAdd.hAdd, congrFun', CochainComplex.prev_nat_succ, Eq.refl
29 instances, coercions and auxiliary constants left out.

Tactic trace: 2 steps
Open to load the checked before-and-after goal states.
```
lemma CochainComplex.prev_nat (j : ℕ) : (ComplexShape.up ℕ).prev j = j - 1 := by
…
```