Description: Implicit substitution inference for ordered pairs. Compare copsex2g . (Contributed by NM, 26-Feb-2014) (Proof shortened by Mario Carneiro, 31-Aug-2015)
Ref | Expression | ||
---|---|---|---|
Hypothesis | copsex2ga.1 | |- ( A = <. x , y >. -> ( ph <-> ps ) ) |
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Assertion | copsex2ga | |- ( A e. ( V X. W ) -> ( ph <-> E. x E. y ( A = <. x , y >. /\ ps ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | copsex2ga.1 | |- ( A = <. x , y >. -> ( ph <-> ps ) ) |
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2 | xpss | |- ( V X. W ) C_ ( _V X. _V ) |
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3 | 2 | sseli | |- ( A e. ( V X. W ) -> A e. ( _V X. _V ) ) |
4 | 1 | copsex2gb | |- ( E. x E. y ( A = <. x , y >. /\ ps ) <-> ( A e. ( _V X. _V ) /\ ph ) ) |
5 | 4 | baibr | |- ( A e. ( _V X. _V ) -> ( ph <-> E. x E. y ( A = <. x , y >. /\ ps ) ) ) |
6 | 3 5 | syl | |- ( A e. ( V X. W ) -> ( ph <-> E. x E. y ( A = <. x , y >. /\ ps ) ) ) |