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feat: expose decidable_of_bool #11625

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Merged
kim-em merged 1 commit into from
Dec 12, 2025
Merged

feat: expose decidable_of_bool #11625

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2 changes: 1 addition & 1 deletion src/Init/PropLemmas.lean
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Expand Up @@ -600,7 +600,7 @@ instance [DecidablePred p] : DecidablePred (p ∘ f) :=

/-- Prove that `a` is decidable by constructing a boolean `b` and a proof that `b ↔ a`.
(This is sometimes taken as an alternate definition of decidability.) -/
def decidable_of_bool : ∀ (b : Bool), (b ↔ a) → Decidable a
@[expose] def decidable_of_bool : ∀ (b : Bool), (b ↔ a) → Decidable a
| true, h => isTrue (h.1 rfl)
| false, h => isFalse (mt h.2 Bool.noConfusion)

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