Theorem fcoi2 5091

Description: Composition of restricted identity and a mapping. (Contributed by NM, 13-Dec-2003.) (Proof shortened by Andrew Salmon, 17-Sep-2011.)

Assertion

Ref	Expression
fcoi2	|- ( F : A --> B -> ( ( _I |` B ) o. F ) = F )

Proof of Theorem fcoi2

Step	Hyp	Ref	Expression
1		df-f 4926	. 2 |- ( F : A --> B <-> ( F Fn A /\ ran F C_ B ) )
2		cores 4844	. . 3 |- ( ran F C_ B -> ( ( _I |` B ) o. F ) = ( _I o. F ) )
3		fnrel 5017	. . . 4 |- ( F Fn A -> Rel F )
4		coi2 4857	. . . 4 |- ( Rel F -> ( _I o. F ) = F )
5	3, 4	syl 14	. . 3 |- ( F Fn A -> ( _I o. F ) = F )
6	2, 5	sylan9eqr 2135	. 2 |- ( ( F Fn A /\ ran F C_ B ) -> ( ( _I |` B ) o. F ) = F )
7	1, 6	sylbi 119	1 |- ( F : A --> B -> ( ( _I |` B ) o. F ) = F )

Syntax hints:   -> wi 4   /\ wa 102   = wceq 1284   C_ wss 2973   _I cid 4043   ran crn 4364   |` cres 4365   o. ccom 4367   Rel wrel 4368   Fn wfn 4917   -->wf 4918

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-io 662  ax-5 1376  ax-7 1377  ax-gen 1378  ax-ie1 1422  ax-ie2 1423  ax-8 1435  ax-10 1436  ax-11 1437  ax-i12 1438  ax-bndl 1439  ax-4 1440  ax-14 1445  ax-17 1459  ax-i9 1463  ax-ial 1467  ax-i5r 1468  ax-ext 2063  ax-sep 3896  ax-pow 3948  ax-pr 3964

This theorem depends on definitions:  df-bi 115  df-3an 921  df-tru 1287  df-nf 1390  df-sb 1686  df-eu 1944  df-mo 1945  df-clab 2068  df-cleq 2074  df-clel 2077  df-nfc 2208  df-ral 2353  df-rex 2354  df-v 2603  df-un 2977  df-in 2979  df-ss 2986  df-pw 3384  df-sn 3404  df-pr 3405  df-op 3407  df-br 3786  df-opab 3840  df-id 4048  df-xp 4369  df-rel 4370  df-cnv 4371  df-co 4372  df-dm 4373  df-rn 4374  df-res 4375  df-fun 4924  df-fn 4925  df-f 4926

This theorem is referenced by:  fcof1o  5449