OAI/Analysis/CircleDomains/Topology/ClosedMapSecondCountable.lean

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1 declarations, 0 contain sorry, 0 declared as axioms

A closed surjection with compact fibers preserves second countability. Finite unions of source basis sets give an explicit countable target basis; no metrizability assertion is assumed.

  1. lemma OAI.CircleDomainRigidity.secondCountable_of_closed_surjection_compact_fibers line 13