Commit 2022-03-17 18:31 3e6e34e4

feat(linear_algebra/matrix): The Weinstein–Aronszajn identity (#12767) Notably this includes the proof of the determinant of a block matrix, which we didn't seem to have in the general case. This also renames some of the lemmas about determinants of block matrices, and adds some missing API for inv_of on matrices. There's some discussion at https://math.stackexchange.com/q/4105846/1896 about whether this name is appropriate, and whether it should be called "Sylvester's determinant theorem" instead.