Metamath Proof Explorer


Theorem nfralseu

Description: Bound-variable hypothesis builder for "all some one" restricted to a class. This is the "all some one" counterpart of nfrals . (Contributed by David A. Wheeler, 21-Jul-2026)

Ref Expression
Hypotheses nfralseu.1
|- F/_ x A
nfralseu.2
|- F/ x ph
nfralseu.3
|- F/ x ps
Assertion nfralseu
|- F/ x AE! y e. A ( ph -> ps )

Proof

Step Hyp Ref Expression
1 nfralseu.1
 |-  F/_ x A
2 nfralseu.2
 |-  F/ x ph
3 nfralseu.3
 |-  F/ x ps
4 df-ralseu
 |-  ( AE! y e. A ( ph -> ps ) <-> ( A. y e. A ( ph -> ps ) /\ E! y e. A ph ) )
5 2 3 nfim
 |-  F/ x ( ph -> ps )
6 1 5 nfralw
 |-  F/ x A. y e. A ( ph -> ps )
7 1 2 nfreuw
 |-  F/ x E! y e. A ph
8 6 7 nfan
 |-  F/ x ( A. y e. A ( ph -> ps ) /\ E! y e. A ph )
9 4 8 nfxfr
 |-  F/ x AE! y e. A ( ph -> ps )