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Theorem imass2 4795
Description: Subset theorem for image. Exercise 22(a) of [Enderton] p. 53. (Contributed by NM, 22-Mar-1998.)
Assertion
Ref Expression
imass2  |-  ( A 
C_  B  ->  ( C " A )  C_  ( C " B ) )

Proof of Theorem imass2
StepHypRef Expression
1 ssres2 4727 . . 3  |-  ( A 
C_  B  ->  ( C  |`  A )  C_  ( C  |`  B ) )
2 rnss 4653 . . 3  |-  ( ( C  |`  A )  C_  ( C  |`  B )  ->  ran  ( C  |`  A )  C_  ran  ( C  |`  B ) )
31, 2syl 14 . 2  |-  ( A 
C_  B  ->  ran  ( C  |`  A ) 
C_  ran  ( C  |`  B ) )
4 df-ima 4441 . 2  |-  ( C
" A )  =  ran  ( C  |`  A )
5 df-ima 4441 . 2  |-  ( C
" B )  =  ran  ( C  |`  B )
63, 4, 53sstr4g 3065 1  |-  ( A 
C_  B  ->  ( C " A )  C_  ( C " B ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    C_ wss 2997   ran crn 4429    |` cres 4430   "cima 4431
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-io 665  ax-5 1381  ax-7 1382  ax-gen 1383  ax-ie1 1427  ax-ie2 1428  ax-8 1440  ax-10 1441  ax-11 1442  ax-i12 1443  ax-bndl 1444  ax-4 1445  ax-17 1464  ax-i9 1468  ax-ial 1472  ax-i5r 1473  ax-ext 2070
This theorem depends on definitions:  df-bi 115  df-3an 926  df-tru 1292  df-nf 1395  df-sb 1693  df-clab 2075  df-cleq 2081  df-clel 2084  df-nfc 2217  df-v 2621  df-un 3001  df-in 3003  df-ss 3010  df-sn 3447  df-pr 3448  df-op 3450  df-br 3838  df-opab 3892  df-xp 4434  df-cnv 4436  df-dm 4438  df-rn 4439  df-res 4440  df-ima 4441
This theorem is referenced by:  funimass1  5077  funimass2  5078  fvimacnv  5398  f1imass  5535  ecinxp  6347  sbthlem1  6645  sbthlem2  6646
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