Metamath Proof Explorer


Theorem r19.32

Description: Theorem 19.32 of Margaris p. 90 with restricted quantifiers, analogous to r19.32v . (Contributed by Alexander van der Vekens, 29-Jun-2017)

Ref Expression
Hypothesis r19.32.1
|- F/ x ph
Assertion r19.32
|- ( A. x e. A ( ph \/ ps ) <-> ( ph \/ A. x e. A ps ) )

Proof

Step Hyp Ref Expression
1 r19.32.1
 |-  F/ x ph
2 1 nfn
 |-  F/ x -. ph
3 2 r19.21
 |-  ( A. x e. A ( -. ph -> ps ) <-> ( -. ph -> A. x e. A ps ) )
4 df-or
 |-  ( ( ph \/ ps ) <-> ( -. ph -> ps ) )
5 4 ralbii
 |-  ( A. x e. A ( ph \/ ps ) <-> A. x e. A ( -. ph -> ps ) )
6 df-or
 |-  ( ( ph \/ A. x e. A ps ) <-> ( -. ph -> A. x e. A ps ) )
7 3 5 6 3bitr4i
 |-  ( A. x e. A ( ph \/ ps ) <-> ( ph \/ A. x e. A ps ) )