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Theorem pweq 3562
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 3166 . . 3  |-  ( A  =  B  ->  (
x  C_  A  <->  x  C_  B
) )
21abbidv 2284 . 2  |-  ( A  =  B  ->  { x  |  x  C_  A }  =  { x  |  x 
C_  B } )
3 df-pw 3561 . 2  |-  ~P A  =  { x  |  x 
C_  A }
4 df-pw 3561 . 2  |-  ~P B  =  { x  |  x 
C_  B }
52, 3, 43eqtr4g 2224 1  |-  ( A  =  B  ->  ~P A  =  ~P B
)
Colors of variables: wff set class
Syntax hints:    -> wi 4    = wceq 1343   {cab 2151    C_ wss 3116   ~Pcpw 3559
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 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-11 1494  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-ext 2147
This theorem depends on definitions:  df-bi 116  df-tru 1346  df-nf 1449  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161  df-in 3122  df-ss 3129  df-pw 3561
This theorem is referenced by:  pweqi  3563  pweqd  3564  axpweq  4150  pwexg  4159  pwssunim  4262  ordpwsucexmid  4547  fival  6935  istopg  12637  istopon  12651  eltg  12692  tgdom  12712  ntrval  12750
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