812c47d463
The main issue is nontermination for problems that do not have solution. When using dependent coercions, we keep creating goals of the form `CoeSort ... (coe (coe (coe ...))) ...`. Same for `CoeFun`. I am considering simplifying it even further, and making sure `CoeDep` can be used at most once in a sequence of coercions `CoeTC`. Another option is to use a very small amount of fuel to guarantee termination when solving coercion TC problems. cc @Kha @dselsam
15 lines
285 B
Text
15 lines
285 B
Text
new_frontend
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universes u
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def Below (n : Nat) : Nat → Prop :=
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(· < n)
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def f {n : Nat} (v : Subtype (Below n)) : Nat :=
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v + 1
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instance pred2subtype {α : Type u} : CoeSort (α → Prop) (Type u) :=
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CoeSort.mk (fun p => Subtype p)
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def g {n : Nat} (v : Below n) : Nat :=
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v.val + 1
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