mathlib

57a0789b - chore(topology/order): relate Sup and Inf of topologies to `generate_from` (#9045)

chore(topology/order): relate Sup and Inf of topologies to `generate_from` (#9045) Since there is a Galois insertion between `generate_from : set (set α) → topological_space α` and the "forgetful functor" `topological_space α → set (set α)`, all kinds of lemmas about the interaction of `generate_from` and the ordering on topologies automatically follow. But it is hard to use the Galois insertion lemmas directly, because the Galois insertion is actually provided for the dual order on topologies, which confuses Lean. Here we re-state most of the Galois insertion API in this special case. Co-authored-by: Johan Commelin <johan@commelin.net>