mathlib

1fbe1183 - golf(set_theory/game/pgame): golf `neg_le_neg_iff` (#14726)

golf(set_theory/game/pgame): golf `neg_le_neg_iff` (#14726) Also in this PR: + slightly golf `subsequent.trans` + replace `->` by `→` + replace a nonterminal `simp` by `dsimp`