Theorem ax7v1 1937

Description: First of two weakened versions of ax7v 1936, with an extra dv condition on x , z, see comments there. (Contributed by BJ, 7-Dec-2020.)

Assertion

Ref	Expression
ax7v1	|- ( x = y -> ( x = z -> y = z ) )

Distinct variable groups:   x, y   x, z

Proof of Theorem ax7v1

Step	Hyp	Ref	Expression
1		ax7v 1936	1 |- ( x = y -> ( x = z -> y = z ) )

Syntax hints:   -> wi 4

This theorem was proved from axioms:  ax-7 1935

This theorem is referenced by:  equid  1939  ax7  1943  ax13  2249