Theorem feq123d 5328

Description: Equality deduction for functions. (Contributed by Paul Chapman, 22-Jun-2011.)

Hypotheses

Ref	Expression
feq12d.1	|- ( ph -> F = G )
feq12d.2	|- ( ph -> A = B )
feq123d.3	|- ( ph -> C = D )

Assertion

Ref	Expression
feq123d	|- ( ph -> ( F : A --> C <-> G : B --> D ) )

Proof of Theorem feq123d

Step	Hyp	Ref	Expression
1		feq12d.1	. . 3 |- ( ph -> F = G )
2		feq12d.2	. . 3 |- ( ph -> A = B )
3	1, 2	feq12d 5327	. 2 |- ( ph -> ( F : A --> C <-> G : B --> C ) )
4		feq123d.3	. . 3 |- ( ph -> C = D )
5		feq3 5322	. . 3 |- ( C = D -> ( G : B --> C <-> G : B --> D ) )
6	4, 5	syl 14	. 2 |- ( ph -> ( G : B --> C <-> G : B --> D ) )
7	3, 6	bitrd 187	1 |- ( ph -> ( F : A --> C <-> G : B --> D ) )

Syntax hints:   -> wi 4   <-> wb 104   = wceq 1343   -->wf 5184

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-ext 2147

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-v 2728  df-un 3120  df-in 3122  df-ss 3129  df-sn 3582  df-pr 3583  df-op 3585  df-br 3983  df-opab 4044  df-rel 4611  df-cnv 4612  df-co 4613  df-dm 4614  df-rn 4615  df-fun 5190  df-fn 5191  df-f 5192

This theorem is referenced by:  feq123  5329  feq23d  5333