b5122b6a7b
This change * moves `termination_by` and `decreasing_by` next to the function they apply to * simplify the syntax of `termination_by` * apply the `decreasing_by` goal to all goals at once, for better interactive use. See the section in `RELEASES.md` for more details and migration advise. This is a hard breaking change, requiring developers to touch every `termination_by` in their code base. We decided to still do it as a hard-breaking change, because supporting both old and new syntax at the same time would be non-trivial, and not save that much. Moreover, this requires changes to some metaprograms that developers might have written, and supporting both syntaxes at the same time would make _their_ migration harder.
15 lines
260 B
Text
15 lines
260 B
Text
mutual
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def fn (f : α → α) (a : α) (n : Nat) : α :=
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match n with
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| 0 => a
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| n+1 => gn f (f (f a)) (f a) n
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termination_by n
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def gn (f : α → α) (a b : α) (n : Nat) : α :=
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match n with
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| 0 => b
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| n+1 => fn f (f b) n
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termination_by n
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end
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