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Theorem decidr 14633
Description: Sufficient condition for being decidable in another class. (Contributed by BJ, 19-Feb-2022.)
Hypothesis
Ref Expression
decidr.1  |-  ( ph  ->  ( x  e.  B  ->  ( x  e.  A  \/  -.  x  e.  A
) ) )
Assertion
Ref Expression
decidr  |-  ( ph  ->  A DECIDin  B )
Distinct variable groups:    x, A    x, B    ph, x

Proof of Theorem decidr
StepHypRef Expression
1 decidr.1 . . . 4  |-  ( ph  ->  ( x  e.  B  ->  ( x  e.  A  \/  -.  x  e.  A
) ) )
2 df-dc 835 . . . 4  |-  (DECID  x  e.  A  <->  ( x  e.  A  \/  -.  x  e.  A ) )
31, 2imbitrrdi 162 . . 3  |-  ( ph  ->  ( x  e.  B  -> DECID  x  e.  A ) )
43alrimiv 1874 . 2  |-  ( ph  ->  A. x ( x  e.  B  -> DECID  x  e.  A
) )
5 df-dcin 14631 . . 3  |-  ( A DECIDin  B  <->  A. x  e.  B DECID  x  e.  A
)
6 df-ral 2460 . . 3  |-  ( A. x  e.  B DECID  x  e.  A 
<-> 
A. x ( x  e.  B  -> DECID  x  e.  A
) )
75, 6bitri 184 . 2  |-  ( A DECIDin  B  <->  A. x
( x  e.  B  -> DECID  x  e.  A ) )
84, 7sylibr 134 1  |-  ( ph  ->  A DECIDin  B )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    \/ wo 708  DECID wdc 834   A.wal 1351    e. wcel 2148   A.wral 2455   DECIDin wdcin 14630
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-5 1447  ax-gen 1449  ax-17 1526
This theorem depends on definitions:  df-bi 117  df-dc 835  df-ral 2460  df-dcin 14631
This theorem is referenced by:  decidin  14634  uzdcinzz  14635  sumdc2  14636
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