Commit 2021-06-23 17:29 dd5074c4
View on Github →feat(analysis/normed_space/basic): add has_nnnorm (#7986)
We create here classes has_nndist
and has_nnnorm
that are variants of has_dist
and has_norm
taking values in ℝ≥0
. Obvious instances are pseudo_metric_space
and semi_normed_group
.
These are not used that much in mathlib, but for example has_nnnorm
is quite convenient for LTE.