3ab2c714ec
the support for mutual structural recursion (new since #4575) is extended so that Lean tries to infer it even without annotations. * The error message when termination checking fails looks quite different now. Maybe a bit better, maybe with more room for improvements. * If there are too many combinations (with an arbitrary cut-off) for a given argument type, it will just give up and ask the user to use `termination_by structural`. * It is now legal to specify `termination_by structural` on not necessarily all functions of a clique; this simply restricts the combinations of arguments that Lean considers. --------- Co-authored-by: Tobias Grosser <tobias@grosser.es>
11 lines
410 B
Text
11 lines
410 B
Text
1673.lean:1:4-1:9: error: fail to show termination for
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foo.a
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with errors
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failed to infer structural recursion:
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Not considering parameter n of foo.a:
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it is unchanged in the recursive calls
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Not considering parameter nope of foo.a:
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it is unchanged in the recursive calls
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no parameters suitable for structural recursion
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well-founded recursion cannot be used, 'foo.a' does not take any (non-fixed) arguments
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