Theorem feq2 5394

Description: Equality theorem for functions. (Contributed by NM, 1-Aug-1994.)

Assertion

Ref	Expression
feq2	|- ( A = B -> ( F : A --> C <-> F : B --> C ) )

Proof of Theorem feq2

Step	Hyp	Ref	Expression
1		fneq2 5348	. . 3 |- ( A = B -> ( F Fn A <-> F Fn B ) )
2	1	anbi1d 465	. 2 |- ( A = B -> ( ( F Fn A /\ ran F C_ C ) <-> ( F Fn B /\ ran F C_ C ) ) )
3		df-f 5263	. 2 |- ( F : A --> C <-> ( F Fn A /\ ran F C_ C ) )
4		df-f 5263	. 2 |- ( F : B --> C <-> ( F Fn B /\ ran F C_ C ) )
5	2, 3, 4	3bitr4g 223	1 |- ( A = B -> ( F : A --> C <-> F : B --> C ) )

Syntax hints:   -> wi 4   /\ wa 104   <-> wb 105   = wceq 1364   C_ wss 3157   ran crn 4665   Fn wfn 5254   -->wf 5255

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-5 1461  ax-gen 1463  ax-4 1524  ax-17 1540  ax-ext 2178

This theorem depends on definitions:  df-bi 117  df-cleq 2189  df-fn 5262  df-f 5263

This theorem is referenced by:  feq23  5396  feq2d  5398  feq2i  5404  f00  5452  f0dom0  5454  f1eq2  5462  fressnfv  5752  tfrcllemsucfn  6420  tfrcllemsucaccv  6421  tfrcllembxssdm  6423  tfrcllembfn  6424  tfrcllemaccex  6428  tfrcllemres  6429  tfrcldm  6430  tfrcl  6431  mapvalg  6726  map0g  6756  ac6sfi  6968  isomni  7211  ismkv  7228  iswomni  7240  isghm  13449