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Diff — Invertible matrix

Revision #3237 → #3779 · back to history

addedDeterminant of a matrix45fe814d0b4f
addedElementary matrix (transvection)8910d14ee21d
addedAdjugate matrixc8d4f958ab6b
modifiedSchur complementfce66cdf6cae
FieldFrom #3237To #3779
mathlib.moduleMathlib.LinearAlgebra.Matrix.SchurComplementMathlib.Data.Matrix.Block
noteThe Schur complement `D - C A⁻¹ B` appears throughout `Mathlib.LinearAlgebra.Matrix.SchurComplement` in lemmas like `Matrix.fromBlocks_eq_of_invertible_top_left` and `Matrix.det_fromBlocks₁₁`.The Schur complement `D - C A⁻¹ B` appears throughout `Mathlib.LinearAlgebra.Matrix.SchurComplement` in lemmas like `Matrix.fromBlocks_eq_of_invertible_top_left` and `Matrix.det_fromBlocks₁₁`, built on `Matrix.fromBlocks` from `Mathlib.Data.Matrix.Block`.
addedInvertible iff full rankdf11f8a61b8c
modifiedInvertible iff trivial kernelec7164d0b30b
FieldFrom #3237To #3779
mathlib.moduleMathlib.LinearAlgebra.BasicMathlib.Algebra.Module.Submodule.Ker
modifiedInvertible matrix is product of elementary matricesb5462efbcab9
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mathlib.decl—Matrix.diagonal_transvection_induction_of_det_ne_zero
mathlib.match_kind—generalization
mathlib.module—Mathlib.LinearAlgebra.Matrix.Transvection
noteMathlib defines `Matrix.TransvectionStruct` and proves every invertible matrix is a product of diagonal and transvection matrices (`diagonal_transvection_induction`), but no statement in terms of generic elementary matrices.Mathlib defines `Matrix.TransvectionStruct` and proves every invertible matrix is a product of diagonal and transvection matrices (`diagonal_transvection_induction_of_det_ne_zero`), but no statement in terms of generic elementary matrices.
provenanceaiai-moderated
statusnot_formalizedpartial
modifiedRows of inverse orthonormal to columns534eb6430ac0
FieldFrom #3237To #3779
noteNo statement framing the rows of `A⁻¹` as biorthogonal to the columns of `A` is in Mathlib.No statement framing the rows of `A⁻¹` as biorthogonal to the columns of `A` is in Mathlib. (Note: the source's word `orthonormal` here is a misnomer for `biorthogonal` — the pairing yields Kronecker deltas via `UV = I`, not an orthonormality condition.)
modifiedOne-sided inverse implies two-sided11eaf6802719
FieldFrom #3237To #3779
moderation_proposal.fields—{"mathlib":{"decl":"mul_eq_one_comm","module":"Mathlib.Algebra.Group.Monoid","match_kind":"generalization"}}
moderation_proposal.reason—`mul_eq_one_comm` lives in `Mathlib.Algebra.Group.Monoid` (general `MulOne`/`IsDedekindFiniteMonoid`); the cited module `Mathlib.LinearAlgebra.Matrix.SemiringInverse` does not contain a declaration named `mul_eq_one_comm`.
addedLU decomposition3440aa149a8f