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Theorem funfvima2d 38469
Description: A function's value in a preimage belongs to the image. (Contributed by Stanislas Polu, 9-Mar-2020.)
Hypothesis
Ref Expression
funfvima2d.1  |-  ( ph  ->  F : A --> B )
Assertion
Ref Expression
funfvima2d  |-  ( (
ph  /\  x  e.  A )  ->  ( F `  x )  e.  ( F " A
) )

Proof of Theorem funfvima2d
StepHypRef Expression
1 funfvima2d.1 . . . 4  |-  ( ph  ->  F : A --> B )
2 ffun 6048 . . . 4  |-  ( F : A --> B  ->  Fun  F )
31, 2syl 17 . . 3  |-  ( ph  ->  Fun  F )
4 ssid 3624 . . . . 5  |-  A  C_  A
54a1i 11 . . . 4  |-  ( ph  ->  A  C_  A )
6 fdm 6051 . . . . 5  |-  ( F : A --> B  ->  dom  F  =  A )
71, 6syl 17 . . . 4  |-  ( ph  ->  dom  F  =  A )
85, 7sseqtr4d 3642 . . 3  |-  ( ph  ->  A  C_  dom  F )
9 funfvima2 6493 . . 3  |-  ( ( Fun  F  /\  A  C_ 
dom  F )  -> 
( x  e.  A  ->  ( F `  x
)  e.  ( F
" A ) ) )
103, 8, 9syl2anc 693 . 2  |-  ( ph  ->  ( x  e.  A  ->  ( F `  x
)  e.  ( F
" A ) ) )
1110imp 445 1  |-  ( (
ph  /\  x  e.  A )  ->  ( F `  x )  e.  ( F " A
) )
Colors of variables: wff setvar class
Syntax hints:    -> wi 4    /\ wa 384    = wceq 1483    e. wcel 1990    C_ wss 3574   dom cdm 5114   "cima 5117   Fun wfun 5882   -->wf 5884   ` cfv 5888
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-sep 4781  ax-nul 4789  ax-pr 4906
This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ral 2917  df-rex 2918  df-rab 2921  df-v 3202  df-sbc 3436  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-nul 3916  df-if 4087  df-sn 4178  df-pr 4180  df-op 4184  df-uni 4437  df-br 4654  df-opab 4713  df-id 5024  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-fv 5896
This theorem is referenced by:  imo72b2lem1  38471
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