16 lines
621 B
Text
16 lines
621 B
Text
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inductive foo :=
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| a | b
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open foo
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-- This test demonstrates we need to disable local instances.
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set_option elaborator.local_instances false
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definition decidable_eq_foo [instance] : ∀ f₁ f₂ : foo, decidable (f₁ = f₂)
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| a a := by left; reflexivity
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| a b := by right; contradiction
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| b a := by right; contradiction
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-- If we don't disable the local_instances, then type class resolution synthesizes the term (decidable_eq_foo b b) which is not a
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-- valid "recursive application", and the recursive equation compiler fails with a cryptic message saying we should try to use well-founded recursion.
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| b b := _
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