Metamath Proof Explorer


Definition df-als

Description: Define "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)

Ref Expression
Assertion df-als Could not format assertion : No typesetting found for |- ( AE x ( ph -> ps ) <-> ( A. x ( ph -> ps ) /\ E. x ph ) ) with typecode |-

Detailed syntax breakdown

Step Hyp Ref Expression
0 vx setvar x
1 wph wff φ
2 wps wff ψ
3 1 2 0 wals Could not format AE x ( ph -> ps ) : No typesetting found for wff AE x ( ph -> ps ) with typecode wff
4 1 2 wi wff φ ψ
5 4 0 wal wff x φ ψ
6 1 0 wex wff x φ
7 5 6 wa wff x φ ψ x φ
8 3 7 wb Could not format ( AE x ( ph -> ps ) <-> ( A. x ( ph -> ps ) /\ E. x ph ) ) : No typesetting found for wff ( AE x ( ph -> ps ) <-> ( A. x ( ph -> ps ) /\ E. x ph ) ) with typecode wff