mathlib

9db43a5f - chore(data/nat/basic): remove pos_iff_ne_zero' (#1610)

chore(data/nat/basic): remove pos_iff_ne_zero' (#1610) This used to be different from pos_iff_ne_zero because the latter was phrased in terms of `n > 0`, not `0 < n`. Since #1436 they are the same.