Metamath Proof Explorer


Theorem nfals

Description: Bound-variable hypothesis builder for "all some". (Contributed by David A. Wheeler, 12-Jul-2026)

Ref Expression
Hypotheses nfals.1 x φ
nfals.2 x ψ
Assertion nfals Could not format assertion : No typesetting found for |- F/ x AE y ( ph -> ps ) with typecode |-

Proof

Step Hyp Ref Expression
1 nfals.1 x φ
2 nfals.2 x ψ
3 df-als Could not format ( AE y ( ph -> ps ) <-> ( A. y ( ph -> ps ) /\ E. y ph ) ) : No typesetting found for |- ( AE y ( ph -> ps ) <-> ( A. y ( ph -> ps ) /\ E. y ph ) ) with typecode |-
4 1 2 nfim x φ ψ
5 4 nfal x y φ ψ
6 1 nfex x y φ
7 5 6 nfan x y φ ψ y φ
8 3 7 nfxfr Could not format F/ x AE y ( ph -> ps ) : No typesetting found for |- F/ x AE y ( ph -> ps ) with typecode |-