Theorem elmpt2cl1 6877

Description: If a two-parameter class is not empty, the first argument is in its nominal domain. (Contributed by FL, 15-Oct-2012.) (Revised by Stefan O'Rear, 7-Mar-2015.)

Hypothesis

Ref	Expression
elmpt2cl.f	|- F = ( x e. A , y e. B |-> C )

Assertion

Ref	Expression
elmpt2cl1	|- ( X e. ( S F T ) -> S e. A )

Distinct variable groups:   x, A, y   x, B, y

Allowed substitution hints:   C( x, y)   S( x, y)   T( x, y)   F( x, y)   X( x, y)

Proof of Theorem elmpt2cl1

Step	Hyp	Ref	Expression
1		elmpt2cl.f	. . 3 |- F = ( x e. A , y e. B |-> C )
2	1	elmpt2cl 6876	. 2 |- ( X e. ( S F T ) -> ( S e. A /\ T e. B ) )
3	2	simpld 475	1 |- ( X e. ( S F T ) -> S e. A )

Syntax hints:   -> wi 4   = wceq 1483   e. wcel 1990  (class class class)co 6650   |-> cmpt2 6652

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-8 1992  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-sep 4781  ax-nul 4789  ax-pow 4843  ax-pr 4906

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-ral 2917  df-rex 2918  df-rab 2921  df-v 3202  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-nul 3916  df-if 4087  df-sn 4178  df-pr 4180  df-op 4184  df-uni 4437  df-br 4654  df-opab 4713  df-xp 5120  df-dm 5124  df-iota 5851  df-fv 5896  df-ov 6653  df-oprab 6654  df-mpt2 6655

This theorem is referenced by:  iccssico2  12247  mhmrcl1  17338  rhmrcl1  18719  cncfrss  22694  lbioc  39739