Commit 2025-01-23 19:32 d82bc8c0

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feat(Algebra/Homology): quasi-isomorphisms are stable under retracts and have the 2/3 property (#20221)

Estimated changes

Modified Mathlib.lean

Modified Mathlib/Algebra/Homology/QuasiIso.lean

modified theorem HomologicalComplex.mem_quasiIso_iff

added theorem quasiIsoAt_of_retract

added theorem quasiIso_of_retractArrow

Created Mathlib/Algebra/Homology/ShortComplex/Retract.lean

added theorem CategoryTheory.ShortComplex.quasiIso_of_retract