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Theorem sspw 3684
Description: The powerclass preserves inclusion. See sspwb 4334 for the biconditional version. (Contributed by NM, 13-Oct-1996.) Extract forward implication of sspwb 4334 since it requires fewer axioms. (Revised by BJ, 13-Apr-2024.)
Assertion
Ref Expression
sspw  |-  ( A 
C_  B  ->  ~P A  C_  ~P B )

Proof of Theorem sspw
Dummy variable  x is distinct from all other variables.
StepHypRef Expression
1 sstr2 3247 . . . 4  |-  ( x 
C_  A  ->  ( A  C_  B  ->  x  C_  B ) )
21com12 30 . . 3  |-  ( A 
C_  B  ->  (
x  C_  A  ->  x 
C_  B ) )
3 velpw 3678 . . 3  |-  ( x  e.  ~P A  <->  x  C_  A
)
4 velpw 3678 . . 3  |-  ( x  e.  ~P B  <->  x  C_  B
)
52, 3, 43imtr4g 205 . 2  |-  ( A 
C_  B  ->  (
x  e.  ~P A  ->  x  e.  ~P B
) )
65ssrdv 3246 1  |-  ( A 
C_  B  ->  ~P A  C_  ~P B )
Colors of variables: wff set class
Syntax hints:    -> wi 4    e. wcel 2205    C_ wss 3213   ~Pcpw 3671
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2216
This theorem depends on definitions:  df-bi 117  df-tru 1401  df-nf 1510  df-sb 1812  df-clab 2221  df-cleq 2227  df-clel 2230  df-nfc 2375  df-v 2817  df-in 3219  df-ss 3226  df-pw 3673
This theorem is referenced by:  sspwi  3685  sspwd  3686
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