basic): `isometry.norm_map_of_map_zero` (#14836)

Commit

3 years ago

feat(analysis/normed/group/basic): `isometry.norm_map_of_map_zero` (#14836) Add the lemma that an isometry of `semi_normed_group`s that preserves 0 preserves the norm.

Author

jsm28

Parents

cf118ee6

mathlib 10a52752 - feat(analysis/normed/group/basic): `isometry.norm_map_of_map_zero` (#14836)

mathlib
10a52752 - feat(analysis/normed/group/basic): `isometry.norm_map_of_map_zero` (#14836)