Theorem imaeq1i

Description: Equality theorem for image. (Contributed by NM, 21-Dec-2008)

	Ref	Expression
Hypothesis	imaeq1i.1	|- A = B
Assertion	imaeq1i	|- ( A " C ) = ( B " C )

Proof

Step	Hyp	Ref	Expression
1		imaeq1i.1	|- A = B
2		imaeq1	|- ( A = B -> ( A " C ) = ( B " C ) )
3	1 2	ax-mp	|- ( A " C ) = ( B " C )