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Theorem ax11v 1307
Description: This is a version of ax-11o 1260 when the variables are distinct. Axiom (C8) of [Monk2] p. 105. See theorem ax11v2 1257 for the rederivation of ax-11o 1260 from this theorem.
Assertion
Ref Expression
ax11v |- (x = y -> (ph -> A.x(x = y -> ph)))
Distinct variable group:   x,y

Proof of Theorem ax11v
StepHypRef Expression
1 ax-16 1252 . . . 4 |- (A.x x = y -> ((x = y -> ph) -> A.x(x = y -> ph)))
2 ax-1 4 . . . 4 |- (ph -> (x = y -> ph))
31, 2syl5 21 . . 3 |- (A.x x = y -> (ph -> A.x(x = y -> ph)))
43a1d 12 . 2 |- (A.x x = y -> (x = y -> (ph -> A.x(x = y -> ph))))
5 ax-11o 1260 . 2 |- (-. A.x x = y -> (x = y -> (ph -> A.x(x = y -> ph))))
64, 5pm2.61i 132 1 |- (x = y -> (ph -> A.x(x = y -> ph)))
Colors of variables: wff set class
Syntax hints:   -> wi 3  A.wal 995   = wceq 997
This theorem is referenced by:  sb56 1308
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-16 1252  ax-11o 1260
Copyright terms: Public domain