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Theorem 2eu3 1494
Description: Double existential uniqueness.
Assertion
Ref Expression
2eu3 |- (A.xA.y(E*xph \/ E*yph) -> ((E!xE!yph /\ E!yE!xph) <-> (E!xE.yph /\ E!yE.xph)))

Proof of Theorem 2eu3
StepHypRef Expression
1 hbmo1 1448 . . . . 5 |- (E*yph -> A.yE*yph)
2119.31 1128 . . . 4 |- (A.y(E*xph \/ E*yph) <-> (A.yE*xph \/ E*yph))
32albii 1040 . . 3 |- (A.xA.y(E*xph \/ E*yph) <-> A.x(A.yE*xph \/ E*yph))
4 hbmo1 1448 . . . . 5 |- (E*xph -> A.xE*xph)
54hbal 1046 . . . 4 |- (A.yE*xph -> A.xA.yE*xph)
6519.32 1127 . . 3 |- (A.x(A.yE*xph \/ E*yph) <-> (A.yE*xph \/ A.xE*yph))
73, 6bitri 180 . 2 |- (A.xA.y(E*xph \/ E*yph) <-> (A.yE*xph \/ A.xE*yph))
8 2eu1 1492 . . . . . . 7 |- (A.yE*xph -> (E!yE!xph <-> (E!yE.xph /\ E!xE.yph)))
98biimpd 160 . . . . . 6 |- (A.yE*xph -> (E!yE!xph -> (E!yE.xph /\ E!xE.yph)))
10 ancom 446 . . . . . 6 |- ((E!yE.xph /\ E!xE.yph) <-> (E!xE.yph /\ E!yE.xph))
119, 10syl6ib 219 . . . . 5 |- (A.yE*xph -> (E!yE!xph -> (E!xE.yph /\ E!yE.xph)))
1211adantld 399 . . . 4 |- (A.yE*xph -> ((E!xE!yph /\ E!yE!xph) -> (E!xE.yph /\ E!yE.xph)))
13 2eu1 1492 . . . . . 6 |- (A.xE*yph -> (E!xE!yph <-> (E!xE.yph /\ E!yE.xph)))
1413biimpd 160 . . . . 5 |- (A.xE*yph -> (E!xE!yph -> (E!xE.yph /\ E!yE.xph)))
1514adantrd 400 . . . 4 |- (A.xE*yph -> ((E!xE!yph /\ E!yE!xph) -> (E!xE.yph /\ E!yE.xph)))
1612, 15jaoi 348 . . 3 |- ((A.yE*xph \/ A.xE*yph) -> ((E!xE!yph /\ E!yE!xph) -> (E!xE.yph /\ E!yE.xph)))
17 2exeu 1489 . . . 4 |- ((E!xE.yph /\ E!yE.xph) -> E!xE!yph)
18 2exeu 1489 . . . . 5 |- ((E!yE.xph /\ E!xE.yph) -> E!yE!xph)
1918ancoms 447 . . . 4 |- ((E!xE.yph /\ E!yE.xph) -> E!yE!xph)
2017, 19jca 295 . . 3 |- ((E!xE.yph /\ E!yE.xph) -> (E!xE!yph /\ E!yE!xph))
2116, 20impbid1 528 . 2 |- ((A.yE*xph \/ A.xE*yph) -> ((E!xE!yph /\ E!yE!xph) <-> (E!xE.yph /\ E!yE.xph)))
227, 21sylbi 206 1 |- (A.xA.y(E*xph \/ E*yph) -> ((E!xE!yph /\ E!yE!xph) <-> (E!xE.yph /\ E!yE.xph)))
Colors of variables: wff set class
Syntax hints:   -> wi 3   <-> wb 153   \/ wo 229   /\ wa 230  A.wal 995  E.wex 1021  E!weu 1422  E*wmo 1423
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 1003  ax-gen 1004  ax-8 1005  ax-10 1007  ax-11 1008  ax-12 1009  ax-17 1012  ax-4 1014  ax-5o 1016  ax-6o 1019  ax-9o 1164  ax-10o 1182  ax-16 1252  ax-11o 1260
This theorem depends on definitions:  df-bi 154  df-or 231  df-an 232  df-ex 1022  df-sb 1214  df-eu 1424  df-mo 1425
Copyright terms: Public domain