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Theorem prlem1 576
Description: A specialized lemma for set theory (axiom of pairing).
Hypotheses
Ref Expression
prlem1.1 |- (ph -> (et <-> ch))
prlem1.2 |- (ps -> -. th)
Assertion
Ref Expression
prlem1 |- (ph -> (ps -> (((ps /\ ch) \/ (th /\ ta )) -> et)))

Proof of Theorem prlem1
StepHypRef Expression
1 prlem1.1 . . . . . 6 |- (ph -> (et <-> ch))
21biimprcd 138 . . . . 5 |- (ch -> (ph -> et))
32adantl 305 . . . 4 |- ((ps /\ ch) -> (ph -> et))
43a1dd 42 . . 3 |- ((ps /\ ch) -> (ph -> (ps -> et)))
5 pm2.24 72 . . . . . 6 |- (th -> (-. th -> et))
6 prlem1.2 . . . . . 6 |- (ps -> -. th)
75, 6syl5 22 . . . . 5 |- (th -> (ps -> et))
87adantr 306 . . . 4 |- ((th /\ ta ) -> (ps -> et))
98a1d 14 . . 3 |- ((th /\ ta ) -> (ph -> (ps -> et)))
104, 9jaoi 275 . 2 |- (((ps /\ ch) \/ (th /\ ta )) -> (ph -> (ps -> et)))
1110com3l 34 1 |- (ph -> (ps -> (((ps /\ ch) \/ (th /\ ta )) -> et)))
Colors of variables: wff set class
Syntax hints:  -. wn 1   -> wi 2   <-> wb 127   \/ wo 195   /\ wa 196
This theorem is referenced by:  zfpair 1891
This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6
This theorem depends on definitions:  df-bi 128  df-or 197  df-an 198
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