Metamath Proof Explorer


Syntax definition wals

Description: Extend wff definition to include "all some" applied to a top-level implication, which means ps is true whenever ph is true, and there is at least one x where ph is true. (Contributed by David A. Wheeler, 20-Oct-2018) (Revised by David A. Wheeler, 12-Jul-2026)

Ref Expression
Assertion wals Could not format assertion : No typesetting found for wff AE x ( ph -> ps ) with typecode wff