Theorem cdeqeq 2810

Description: Distribute conditional equality over equality. (Contributed by Mario Carneiro, 11-Aug-2016.)

Hypotheses

Ref	Expression
cdeqeq.1	|- CondEq ( x = y -> A = B )
cdeqeq.2	|- CondEq ( x = y -> C = D )

Assertion

Ref	Expression
cdeqeq	|- CondEq ( x = y -> ( A = C <-> B = D ) )

Proof of Theorem cdeqeq

Step	Hyp	Ref	Expression
1		cdeqeq.1	. . . 4 |- CondEq ( x = y -> A = B )
2	1	cdeqri 2801	. . 3 |- ( x = y -> A = B )
3		cdeqeq.2	. . . 4 |- CondEq ( x = y -> C = D )
4	3	cdeqri 2801	. . 3 |- ( x = y -> C = D )
5	2, 4	eqeq12d 2095	. 2 |- ( x = y -> ( A = C <-> B = D ) )
6	5	cdeqi 2800	1 |- CondEq ( x = y -> ( A = C <-> B = D ) )

Syntax hints:   <-> wb 103   = wceq 1284  CondEqwcdeq 2798

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1376  ax-gen 1378  ax-4 1440  ax-17 1459  ax-ext 2063

This theorem depends on definitions:  df-bi 115  df-cleq 2074  df-cdeq 2799

This theorem is referenced by: (None)