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Theorem 2eu3 1069
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 1032 . . . . 5 |- (E*yph -> A.yE*yph)
2119.31 766 . . . 4 |- (A.y(E*xph \/ E*yph) <-> (A.yE*xph \/ E*yph))
32bial 695 . . 3 |- (A.xA.y(E*xph \/ E*yph) <-> A.x(A.yE*xph \/ E*yph))
4 hbmo1 1032 . . . . 5 |- (E*xph -> A.xE*xph)
54hbal 700 . . . 4 |- (A.yE*xph -> A.xA.yE*xph)
6519.32 765 . . 3 |- (A.x(A.yE*xph \/ E*yph) <-> (A.yE*xph \/ A.xE*yph))
73, 6bitr 151 . 2 |- (A.xA.y(E*xph \/ E*yph) <-> (A.yE*xph \/ A.xE*yph))
8 2eu1 1067 . . . . . . 7 |- (A.yE*xph -> (E!yE!xph <-> (E!yE.xph /\ E!xE.yph)))
98biimpd 135 . . . . . 6 |- (A.yE*xph -> (E!yE!xph -> (E!yE.xph /\ E!xE.yph)))
10 ancom 333 . . . . . 6 |- ((E!yE.xph /\ E!xE.yph) <-> (E!xE.yph /\ E!yE.xph))
119, 10syl6ib 185 . . . . 5 |- (A.yE*xph -> (E!yE!xph -> (E!xE.yph /\ E!yE.xph)))
1211adantld 307 . . . 4 |- (A.yE*xph -> ((E!xE!yph /\ E!yE!xph) -> (E!xE.yph /\ E!yE.xph)))
13 2eu1 1067 . . . . . 6 |- (A.xE*yph -> (E!xE!yph <-> (E!xE.yph /\ E!yE.xph)))
1413biimpd 135 . . . . 5 |- (A.xE*yph -> (E!xE!yph -> (E!xE.yph /\ E!yE.xph)))
1514adantrd 308 . . . 4 |- (A.xE*yph -> ((E!xE!yph /\ E!yE!xph) -> (E!xE.yph /\ E!yE.xph)))
1612, 15jaoi 275 . . 3 |- ((A.yE*xph \/ A.xE*yph) -> ((E!xE!yph /\ E!yE!xph) -> (E!xE.yph /\ E!yE.xph)))
17 2exeu 1066 . . . . 5 |- ((E!xE.yph /\ E!yE.xph) -> E!xE!yph)
18 2exeu 1066 . . . . . 6 |- ((E!yE.xph /\ E!xE.yph) -> E!yE!xph)
1918ancoms 334 . . . . 5 |- ((E!xE.yph /\ E!yE.xph) -> E!yE!xph)
2017, 19jca 236 . . . 4 |- ((E!xE.yph /\ E!yE.xph) -> (E!xE!yph /\ E!yE!xph))
2120a1i 7 . . 3 |- ((A.yE*xph \/ A.xE*yph) -> ((E!xE.yph /\ E!yE.xph) -> (E!xE!yph /\ E!yE!xph)))
2216, 21impbid 397 . 2 |- ((A.yE*xph \/ A.xE*yph) -> ((E!xE!yph /\ E!yE!xph) <-> (E!xE.yph /\ E!yE.xph)))
237, 22sylbi 174 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 2   <-> wb 127   \/ wo 195   /\ wa 196  A.wal 672  E.wex 678  E!weu 1007  E*wmo 1008
This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-6 675  ax-7 676  ax-gen 677  ax-8 798  ax-9 799  ax-10 800  ax-11 801  ax-12 802  ax-16 922  ax-17 925
This theorem depends on definitions:  df-bi 128  df-or 197  df-an 198  df-ex 679  df-sb 853  df-eu 1009  df-mo 1010
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