Theorem fnop 5291

Description: The first argument of an ordered pair in a function belongs to the function's domain. (Contributed by NM, 8-Aug-1994.)

Assertion

Ref	Expression
fnop	|- ( ( F Fn A /\ <. B , C >. e. F ) -> B e. A )

Proof of Theorem fnop

Step	Hyp	Ref	Expression
1		df-br 3983	. 2 |- ( B F C <-> <. B , C >. e. F )
2		fnbr 5290	. 2 |- ( ( F Fn A /\ B F C ) -> B e. A )
3	1, 2	sylan2br 286	1 |- ( ( F Fn A /\ <. B , C >. e. F ) -> B e. A )

Syntax hints:   -> wi 4   /\ wa 103   e. wcel 2136   <.cop 3579   class class class wbr 3982   Fn wfn 5183

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-14 2139  ax-ext 2147  ax-sep 4100  ax-pow 4153  ax-pr 4187

This theorem depends on definitions:  df-bi 116  df-3an 970  df-tru 1346  df-nf 1449  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-ral 2449  df-rex 2450  df-v 2728  df-un 3120  df-in 3122  df-ss 3129  df-pw 3561  df-sn 3582  df-pr 3583  df-op 3585  df-br 3983  df-opab 4044  df-xp 4610  df-rel 4611  df-dm 4614  df-fun 5190  df-fn 5191

This theorem is referenced by:  2elresin  5299  tfrlem9  6287  tfrexlem  6302