Theorem f1ss 5604

Description: A function that is one-to-one is also one-to-one on some superset of its range. (Contributed by Mario Carneiro, 12-Jan-2013.)

Assertion

Ref	Expression
f1ss	|- ( ( F : A -1-1-> B /\ B C_ C ) -> F : A -1-1-> C )

Proof of Theorem f1ss

Step	Hyp	Ref	Expression
1		f1f 5598	. . 3 |- ( F : A -1-1-> B -> F : A --> B )
2		fss 5546	. . 3 |- ( ( F : A --> B /\ B C_ C ) -> F : A --> C )
3	1, 2	sylan 283	. 2 |- ( ( F : A -1-1-> B /\ B C_ C ) -> F : A --> C )
4		df-f1 5382	. . . 4 |- ( F : A -1-1-> B <-> ( F : A --> B /\ Fun `' F ) )
5	4	simprbi 275	. . 3 |- ( F : A -1-1-> B -> Fun `' F )
6	5	adantr 276	. 2 |- ( ( F : A -1-1-> B /\ B C_ C ) -> Fun `' F )
7		df-f1 5382	. 2 |- ( F : A -1-1-> C <-> ( F : A --> C /\ Fun `' F ) )
8	3, 6, 7	sylanbrc 421	1 |- ( ( F : A -1-1-> B /\ B C_ C ) -> F : A -1-1-> C )

This proof depends on syntax axioms:   -> wi 4   /\ wa 104   C_ wss 3220   `'ccnv 4773   Fun wfun 5371   -->wf 5373   -1-1->wf1 5374

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-11 1559  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220

This proof depends on definitions:  df-bi 117  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-in 3226  df-ss 3233  df-f 5381  df-f1 5382

This theorem is used by:  f1sng  5683  domssr  7064  hashf1lem1  11285  ausgrusgrben  16409  uspgrushgr  16421  usgruspgr  16424  uspgr1edc  16481