Syntax Definition walseu 17134

Description: Extend wff definition to include "all some one" applied to a top-level implication, which means ps is true whenever ph is true, and exactly one x satisfies ph. (Contributed by David A. Wheeler, 22-Jul-2026.)

Hypotheses

Ref	Expression
wph	wff ph
wps	wff ps
vx	setvar x

Assertion

Ref	Expression
walseu	wff A.E! x ( ph -> ps )

See definition df-alseu 17136 for more information.