ffbea840bf
If here is only one plausible measure, there is no point having the `GuessLex` code see if it is terminating, running all the tactics, only for the `MkFix` code then run the tactics again. So if there is only one plausible measure (non-mutual recursion with only one varying parameter), just use that measure. Side benefit: If the function isn’t terminating, more detailed error messages are shown (failing proof goals), located at the recursive calls.
28 lines
818 B
Text
28 lines
818 B
Text
terminationFailure.lean:7:2-7:3: error: fail to show termination for
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f.g
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f
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with errors
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structural recursion does not handle mutually recursive functions
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failed to prove termination, use `termination_by` to specify a well-founded relation
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f (x : Nat) : Nat
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f.g (a✝ : Nat) : Nat
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1
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2
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terminationFailure.lean:24:9-24:12: error: fail to show termination for
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h
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with errors
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argument #1 was not used for structural recursion
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failed to eliminate recursive application
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h x
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structural recursion cannot be used
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failed to prove termination, possible solutions:
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- Use `have`-expressions to prove the remaining goals
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- Use `termination_by` to specify a different well-founded relation
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- Use `decreasing_by` to specify your own tactic for discharging this kind of goal
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x : Nat
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⊢ False
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h (x : Nat) : Foo
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Foo.a
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