mathlib

0531cb0c - feat(algebra/classical_lie_algebras): add definitions of missing classical Lie algebras (#3661)

feat(algebra/classical_lie_algebras): add definitions of missing classical Lie algebras (#3661) Copying from the comments I have added at the top of `classical_lie_algebras.lean`: ## Main definitions * `lie_algebra.symplectic.sp` * `lie_algebra.orthogonal.so` * `lie_algebra.orthogonal.so'` * `lie_algebra.orthogonal.so_indefinite_equiv` * `lie_algebra.orthogonal.type_D` * `lie_algebra.orthogonal.type_B` * `lie_algebra.orthogonal.type_D_equiv_so'` * `lie_algebra.orthogonal.type_B_equiv_so'`