mathlib

108b9235 - chore(algebra): add `sub{_mul_action,module,semiring,ring,field,algebra}.copy` (#7220)

chore(algebra): add `sub{_mul_action,module,semiring,ring,field,algebra}.copy` (#7220) We already have this for sub{monoid,group}. With this in place, we can make `coe subalgebra.range` defeq to `set.range` and similar (left for a follow-up).