mathlib3

d60541cc - feat(analysis/seminorm): Add `has_add` and `has_scalar nnreal` (#11414)

feat(analysis/seminorm): Add `has_add` and `has_scalar nnreal` (#11414) Add instances of `has_add` and `has_scalar nnreal` type classes for `seminorm`. Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Eric Wieser <wieser.eric@gmail.com>