Theorem xpeq12i 4489

Description: Equality inference for cross product. (Contributed by FL, 31-Aug-2009.)

Hypotheses

Ref	Expression
xpeq12i.1	|- A = B
xpeq12i.2	|- C = D

Assertion

Ref	Expression
xpeq12i	|- ( A X. C ) = ( B X. D )

Proof of Theorem xpeq12i

Step	Hyp	Ref	Expression
1		xpeq12i.1	. 2 |- A = B
2		xpeq12i.2	. 2 |- C = D
3		xpeq12 4486	. 2 |- ( ( A = B /\ C = D ) -> ( A X. C ) = ( B X. D ) )
4	1, 2, 3	mp2an 418	1 |- ( A X. C ) = ( B X. D )

Syntax hints:   = wceq 1296   X. cxp 4465

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1388  ax-7 1389  ax-gen 1390  ax-ie1 1434  ax-ie2 1435  ax-8 1447  ax-11 1449  ax-4 1452  ax-17 1471  ax-i9 1475  ax-ial 1479  ax-i5r 1480  ax-ext 2077

This theorem depends on definitions:  df-bi 116  df-tru 1299  df-nf 1402  df-sb 1700  df-clab 2082  df-cleq 2088  df-clel 2091  df-opab 3922  df-xp 4473

This theorem is referenced by:  xpssres  4780  imainrect  4910  cnvssrndm  4986