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Theorem f1ss 5407
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
StepHypRef Expression
1 f1f 5401 . . 3  |-  ( F : A -1-1-> B  ->  F : A --> B )
2 fss 5357 . . 3  |-  ( ( F : A --> B  /\  B  C_  C )  ->  F : A --> C )
31, 2sylan 281 . 2  |-  ( ( F : A -1-1-> B  /\  B  C_  C )  ->  F : A --> C )
4 df-f1 5201 . . . 4  |-  ( F : A -1-1-> B  <->  ( F : A --> B  /\  Fun  `' F ) )
54simprbi 273 . . 3  |-  ( F : A -1-1-> B  ->  Fun  `' F )
65adantr 274 . 2  |-  ( ( F : A -1-1-> B  /\  B  C_  C )  ->  Fun  `' F
)
7 df-f1 5201 . 2  |-  ( F : A -1-1-> C  <->  ( F : A --> C  /\  Fun  `' F ) )
83, 6, 7sylanbrc 415 1  |-  ( ( F : A -1-1-> B  /\  B  C_  C )  ->  F : A -1-1-> C )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 103    C_ wss 3121   `'ccnv 4608   Fun wfun 5190   -->wf 5192   -1-1->wf1 5193
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-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-11 1499  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-ext 2152
This theorem depends on definitions:  df-bi 116  df-nf 1454  df-sb 1756  df-clab 2157  df-cleq 2163  df-clel 2166  df-in 3127  df-ss 3134  df-f 5200  df-f1 5201
This theorem is referenced by:  f1sng  5482
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