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Theorem pweq 3518
Description: Equality theorem for power class. (Contributed by NM, 5-Aug-1993.)
Assertion
Ref Expression
pweq  |-  ( A  =  B  ->  ~P A  =  ~P B
)

Proof of Theorem pweq
Dummy variable  x is distinct from all other variables.
StepHypRef Expression
1 sseq2 3126 . . 3  |-  ( A  =  B  ->  (
x  C_  A  <->  x  C_  B
) )
21abbidv 2258 . 2  |-  ( A  =  B  ->  { x  |  x  C_  A }  =  { x  |  x 
C_  B } )
3 df-pw 3517 . 2  |-  ~P A  =  { x  |  x 
C_  A }
4 df-pw 3517 . 2  |-  ~P B  =  { x  |  x 
C_  B }
52, 3, 43eqtr4g 2198 1  |-  ( A  =  B  ->  ~P A  =  ~P B
)
Colors of variables: wff set class
Syntax hints:    -> wi 4    = wceq 1332   {cab 2126    C_ wss 3076   ~Pcpw 3515
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 1424  ax-7 1425  ax-gen 1426  ax-ie1 1470  ax-ie2 1471  ax-8 1483  ax-11 1485  ax-4 1488  ax-17 1507  ax-i9 1511  ax-ial 1515  ax-i5r 1516  ax-ext 2122
This theorem depends on definitions:  df-bi 116  df-tru 1335  df-nf 1438  df-sb 1737  df-clab 2127  df-cleq 2133  df-clel 2136  df-in 3082  df-ss 3089  df-pw 3517
This theorem is referenced by:  pweqi  3519  pweqd  3520  axpweq  4103  pwexg  4112  pwssunim  4214  ordpwsucexmid  4493  fival  6866  istopg  12205  istopon  12219  eltg  12260  tgdom  12280  ntrval  12318
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