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Theorem 2eu3 1451
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 1406 . . . . 5 |- (E*yph -> A.yE*yph)
2119.31 1087 . . . 4 |- (A.y(E*xph \/ E*yph) <-> (A.yE*xph \/ E*yph))
32albii 999 . . 3 |- (A.xA.y(E*xph \/ E*yph) <-> A.x(A.yE*xph \/ E*yph))
4 hbmo1 1406 . . . . 5 |- (E*xph -> A.xE*xph)
54hbal 1005 . . . 4 |- (A.yE*xph -> A.xA.yE*xph)
6519.32 1086 . . 3 |- (A.x(A.yE*xph \/ E*yph) <-> (A.yE*xph \/ A.xE*yph))
73, 6bitr 173 . 2 |- (A.xA.y(E*xph \/ E*yph) <-> (A.yE*xph \/ A.xE*yph))
8 2eu1 1449 . . . . . . 7 |- (A.yE*xph -> (E!yE!xph <-> (E!yE.xph /\ E!xE.yph)))
98biimpd 153 . . . . . 6 |- (A.yE*xph -> (E!yE!xph -> (E!yE.xph /\ E!xE.yph)))
10 ancom 435 . . . . . 6 |- ((E!yE.xph /\ E!xE.yph) <-> (E!xE.yph /\ E!yE.xph))
119, 10syl6ib 212 . . . . 5 |- (A.yE*xph -> (E!yE!xph -> (E!xE.yph /\ E!yE.xph)))
1211adantld 390 . . . 4 |- (A.yE*xph -> ((E!xE!yph /\ E!yE!xph) -> (E!xE.yph /\ E!yE.xph)))
13 2eu1 1449 . . . . . 6 |- (A.xE*yph -> (E!xE!yph <-> (E!xE.yph /\ E!yE.xph)))
1413biimpd 153 . . . . 5 |- (A.xE*yph -> (E!xE!yph -> (E!xE.yph /\ E!yE.xph)))
1514adantrd 391 . . . 4 |- (A.xE*yph -> ((E!xE!yph /\ E!yE!xph) -> (E!xE.yph /\ E!yE.xph)))
1612, 15jaoi 341 . . 3 |- ((A.yE*xph \/ A.xE*yph) -> ((E!xE!yph /\ E!yE!xph) -> (E!xE.yph /\ E!yE.xph)))
17 2exeu 1446 . . . 4 |- ((E!xE.yph /\ E!yE.xph) -> E!xE!yph)
18 2exeu 1446 . . . . 5 |- ((E!yE.xph /\ E!xE.yph) -> E!yE!xph)
1918ancoms 436 . . . 4 |- ((E!xE.yph /\ E!yE.xph) -> E!yE!xph)
2017, 19jca 288 . . 3 |- ((E!xE.yph /\ E!yE.xph) -> (E!xE!yph /\ E!yE!xph))
2116, 20impbid1 517 . 2 |- ((A.yE*xph \/ A.xE*yph) -> ((E!xE!yph /\ E!yE!xph) <-> (E!xE.yph /\ E!yE.xph)))
227, 21sylbi 199 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 146   \/ wo 222   /\ wa 223  A.wal 954  E.wex 980  E!weu 1380  E*wmo 1381
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 962  ax-gen 963  ax-8 964  ax-10 966  ax-11 967  ax-12 968  ax-17 971  ax-4 973  ax-5o 975  ax-6o 978  ax-9o 1123  ax-10o 1140  ax-16 1210  ax-11o 1218
This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225  df-ex 981  df-sb 1172  df-eu 1382  df-mo 1383
Copyright terms: Public domain