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 ) ) |
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 ) ) |