Theorem funprg 5426

Description: A set of two pairs is a function if their first members are different. (Contributed by FL, 26-Jun-2011.)

Assertion

Ref	Expression
funprg	|- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> Fun { <. A , C >. , <. B , D >. } )

Proof of Theorem funprg

Step	Hyp	Ref	Expression
1		simp1l 1052	. . . 4 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> A e. V )
2		simp2l 1054	. . . 4 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> C e. X )
3		funsng 5422	. . . 4 |- ( ( A e. V /\ C e. X ) -> Fun { <. A , C >. } )
4	1, 2, 3	syl2anc 415	. . 3 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> Fun { <. A , C >. } )
5		simp1r 1053	. . . 4 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> B e. W )
6		simp2r 1055	. . . 4 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> D e. Y )
7		funsng 5422	. . . 4 |- ( ( B e. W /\ D e. Y ) -> Fun { <. B , D >. } )
8	5, 6, 7	syl2anc 415	. . 3 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> Fun { <. B , D >. } )
9		dmsnopg 5254	. . . . . 6 |- ( C e. X -> dom { <. A , C >. } = { A } )
10	2, 9	syl 14	. . . . 5 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> dom { <. A , C >. } = { A } )
11		dmsnopg 5254	. . . . . 6 |- ( D e. Y -> dom { <. B , D >. } = { B } )
12	6, 11	syl 14	. . . . 5 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> dom { <. B , D >. } = { B } )
13	10, 12	ineq12d 3433	. . . 4 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> ( dom { <. A , C >. } i^i dom { <. B , D >. } ) = ( { A } i^i { B } ) )
14		disjsn2 3768	. . . . 5 |- ( A =/= B -> ( { A } i^i { B } ) = (/) )
15	14	3ad2ant3 1051	. . . 4 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> ( { A } i^i { B } ) = (/) )
16	13, 15	eqtrd 2271	. . 3 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> ( dom { <. A , C >. } i^i dom { <. B , D >. } ) = (/) )
17		funun 5417	. . 3 |- ( ( ( Fun { <. A , C >. } /\ Fun { <. B , D >. } ) /\ ( dom { <. A , C >. } i^i dom { <. B , D >. } ) = (/) ) -> Fun ( { <. A , C >. } u. { <. B , D >. } ) )
18	4, 8, 16, 17	syl21anc 1277	. 2 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> Fun ( { <. A , C >. } u. { <. B , D >. } ) )
19		df-pr 3712	. . 3 |- { <. A , C >. , <. B , D >. } = ( { <. A , C >. } u. { <. B , D >. } )
20	19	funeqi 5393	. 2 |- ( Fun { <. A , C >. , <. B , D >. } <-> Fun ( { <. A , C >. } u. { <. B , D >. } ) )
21	18, 20	sylibr 134	1 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) /\ A =/= B ) -> Fun { <. A , C >. , <. B , D >. } )

Syntax hints:   -> wi 4   /\ wa 104   /\ w3a 1009   = wceq 1402   e. wcel 2209   =/= wne 2420   u. cun 3218   i^i cin 3219   (/)c0 3520   {csn 3705   {cpr 3706   <.cop 3708   dom cdm 4769   Fun wfun 5366

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-in1 623  ax-in2 624  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-sep 4244  ax-pow 4306  ax-pr 4341

This theorem depends on definitions:  df-bi 117  df-3an 1011  df-tru 1405  df-fal 1408  df-nf 1514  df-sb 1816  df-eu 2089  df-mo 2090  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ne 2421  df-ral 2533  df-rex 2534  df-v 2823  df-dif 3222  df-un 3224  df-in 3226  df-ss 3233  df-nul 3521  df-pw 3687  df-sn 3711  df-pr 3712  df-op 3714  df-br 4126  df-opab 4188  df-id 4433  df-xp 4775  df-rel 4776  df-cnv 4777  df-co 4778  df-dm 4779  df-fun 5374

This theorem is referenced by:  funtpg  5427  funpr  5428  fnprg  5431  2strbasg  13451  2stropg  13452