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Theorem decidr 11126
Description: Sufficient condition for being decidable in another class. (Contributed by BJ, 19-Feb-2022.)
Hypothesis
Ref Expression
decidr.1 (𝜑 → (𝑥𝐵 → (𝑥𝐴 ∨ ¬ 𝑥𝐴)))
Assertion
Ref Expression
decidr (𝜑𝐴 DECIDin 𝐵)
Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝜑,𝑥

Proof of Theorem decidr
StepHypRef Expression
1 decidr.1 . . . 4 (𝜑 → (𝑥𝐵 → (𝑥𝐴 ∨ ¬ 𝑥𝐴)))
2 df-dc 779 . . . 4 (DECID 𝑥𝐴 ↔ (𝑥𝐴 ∨ ¬ 𝑥𝐴))
31, 2syl6ibr 160 . . 3 (𝜑 → (𝑥𝐵DECID 𝑥𝐴))
43alrimiv 1799 . 2 (𝜑 → ∀𝑥(𝑥𝐵DECID 𝑥𝐴))
5 df-dcin 11124 . . 3 (𝐴 DECIDin 𝐵 ↔ ∀𝑥𝐵 DECID 𝑥𝐴)
6 df-ral 2360 . . 3 (∀𝑥𝐵 DECID 𝑥𝐴 ↔ ∀𝑥(𝑥𝐵DECID 𝑥𝐴))
75, 6bitri 182 . 2 (𝐴 DECIDin 𝐵 ↔ ∀𝑥(𝑥𝐵DECID 𝑥𝐴))
84, 7sylibr 132 1 (𝜑𝐴 DECIDin 𝐵)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wo 662  DECID wdc 778  wal 1285  wcel 1436  wral 2355   DECIDin wdcin 11123
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-5 1379  ax-gen 1381  ax-17 1462
This theorem depends on definitions:  df-bi 115  df-dc 779  df-ral 2360  df-dcin 11124
This theorem is referenced by:  decidin  11127  uzdcinzz  11128  sumdc2  11129
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