Theorem otelxp1 4761

Description: The first member of an ordered triple of classes in a cross product belongs to first cross product argument. (Contributed by NM, 28-May-2008.)

Assertion

Ref	Expression
otelxp1	|- ( <. <. A , B >. , C >. e. ( ( R X. S ) X. T ) -> A e. R )

Proof of Theorem otelxp1

Step	Hyp	Ref	Expression
1		opelxp1 4759	. 2 |- ( <. <. A , B >. , C >. e. ( ( R X. S ) X. T ) -> <. A , B >. e. ( R X. S ) )
2		opelxp1 4759	. 2 |- ( <. A , B >. e. ( R X. S ) -> A e. R )
3	1, 2	syl 14	1 |- ( <. <. A , B >. , C >. e. ( ( R X. S ) X. T ) -> A e. R )

Syntax hints:   -> wi 4   e. wcel 2202   <.cop 3672   X. cxp 4723

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 716  ax-5 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-10 1553  ax-11 1554  ax-i12 1555  ax-bndl 1557  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-14 2205  ax-ext 2213  ax-sep 4207  ax-pow 4264  ax-pr 4299

This theorem depends on definitions:  df-bi 117  df-3an 1006  df-tru 1400  df-nf 1509  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2363  df-ral 2515  df-rex 2516  df-v 2804  df-un 3204  df-in 3206  df-ss 3213  df-pw 3654  df-sn 3675  df-pr 3676  df-op 3678  df-opab 4151  df-xp 4731

This theorem is referenced by: (None)