Description: Existential specialization, using implicit substitution. (Contributed by NM, 3-Aug-1995)
Ref | Expression | ||
---|---|---|---|
Hypotheses | spc2ev.1 | |- A e. _V |
|
spc2ev.2 | |- B e. _V |
||
spc2ev.3 | |- ( ( x = A /\ y = B ) -> ( ph <-> ps ) ) |
||
Assertion | spc2ev | |- ( ps -> E. x E. y ph ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | spc2ev.1 | |- A e. _V |
|
2 | spc2ev.2 | |- B e. _V |
|
3 | spc2ev.3 | |- ( ( x = A /\ y = B ) -> ( ph <-> ps ) ) |
|
4 | 3 | spc2egv | |- ( ( A e. _V /\ B e. _V ) -> ( ps -> E. x E. y ph ) ) |
5 | 1 2 4 | mp2an | |- ( ps -> E. x E. y ph ) |