Theorem ax10 1605

Description: Rederivation of ax-10 1396 from original version ax-10o 1604. See theorem ax10o 1603 for the derivation of ax-10o 1604 from ax-10 1396.

This theorem should not be referenced in any proof. Instead, use ax-10 1396 above so that uses of ax-10 1396 can be more easily identified. (Contributed by NM, 16-May-2008.) (New usage is discouraged.)

Assertion

Ref	Expression
ax10	|- ( A. x x = y -> A. y y = x )

Proof of Theorem ax10

Step	Hyp	Ref	Expression
1		ax-10o 1604	. . 3 |- ( A. x x = y -> ( A. x x = y -> A. y x = y ) )
2	1	pm2.43i 43	. 2 |- ( A. x x = y -> A. y x = y )
3		equcomi 1592	. . 3 |- ( x = y -> y = x )
4	3	alimi 1344	. 2 |- ( A. y x = y -> A. y y = x )
5	2, 4	syl 14	1 |- ( A. x x = y -> A. y y = x )

Syntax hints:   -> wi 4   A.wal 1241

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-5 1336  ax-gen 1338  ax-ie2 1383  ax-8 1395  ax-17 1419  ax-i9 1423  ax-10o 1604

This theorem depends on definitions:  df-bi 110

This theorem is referenced by: (None)