Theorem f1eq2 5255

Description: Equality theorem for one-to-one functions. (Contributed by set.mm contributors, 10-Feb-1997.)

Assertion

Ref	Expression
f1eq2	|- (A = B -> (F:A-1-1->C <-> F:B-1-1->C))

Proof of Theorem f1eq2

Step	Hyp	Ref	Expression
1		feq2 5212	. . 3 |- (A = B -> (F:A-->C <-> F:B-->C))
2	1	anbi1d 685	. 2 |- (A = B -> ((F:A-->C /\ Fun `'F) <-> (F:B-->C /\ Fun `'F)))
3		df-f1 4793	. 2 |- (F:A-1-1->C <-> (F:A-->C /\ Fun `'F))
4		df-f1 4793	. 2 |- (F:B-1-1->C <-> (F:B-->C /\ Fun `'F))
5	2, 3, 4	3bitr4g 279	1 |- (A = B -> (F:A-1-1->C <-> F:B-1-1->C))

Syntax hints:   -> wi 4   <-> wb 176   /\ wa 358   = wceq 1642  `'ccnv 4772  Fun wfun 4776  -->wf 4778  -1-1->wf1 4779

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-11 1746  ax-ext 2334

This theorem depends on definitions:  df-bi 177  df-an 360  df-ex 1542  df-cleq 2346  df-fn 4791  df-f 4792  df-f1 4793

This theorem is referenced by:  f1oeq2  5283  dflec3  6222  nclenc  6223