Metamath Proof Explorer


Theorem dfralseu2

Description: The bounded "all some one" form is the general form with the class membership folded into the antecedent. This is the "all some one" counterpart of dfrals2 . (Contributed by David A. Wheeler, 21-Jul-2026)

Ref Expression
Assertion dfralseu2
|- ( AE! x e. A ( ph -> ps ) <-> AE! x ( ( x e. A /\ ph ) -> ps ) )

Proof

Step Hyp Ref Expression
1 df-ral
 |-  ( A. x e. A ( ph -> ps ) <-> A. x ( x e. A -> ( ph -> ps ) ) )
2 impexp
 |-  ( ( ( x e. A /\ ph ) -> ps ) <-> ( x e. A -> ( ph -> ps ) ) )
3 2 albii
 |-  ( A. x ( ( x e. A /\ ph ) -> ps ) <-> A. x ( x e. A -> ( ph -> ps ) ) )
4 1 3 bitr4i
 |-  ( A. x e. A ( ph -> ps ) <-> A. x ( ( x e. A /\ ph ) -> ps ) )
5 df-reu
 |-  ( E! x e. A ph <-> E! x ( x e. A /\ ph ) )
6 4 5 anbi12i
 |-  ( ( A. x e. A ( ph -> ps ) /\ E! x e. A ph ) <-> ( A. x ( ( x e. A /\ ph ) -> ps ) /\ E! x ( x e. A /\ ph ) ) )
7 df-ralseu
 |-  ( AE! x e. A ( ph -> ps ) <-> ( A. x e. A ( ph -> ps ) /\ E! x e. A ph ) )
8 df-alseu
 |-  ( AE! x ( ( x e. A /\ ph ) -> ps ) <-> ( A. x ( ( x e. A /\ ph ) -> ps ) /\ E! x ( x e. A /\ ph ) ) )
9 6 7 8 3bitr4i
 |-  ( AE! x e. A ( ph -> ps ) <-> AE! x ( ( x e. A /\ ph ) -> ps ) )