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.
16 lines
508 B
Text
16 lines
508 B
Text
/-!
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This module systematically tests the relative placement of `decreasing_by` and `where`.
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-/
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-- For concise recursive definition that need well-founded recursion
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-- and `decreasing_by` tactics that would fail if run on the wrong function
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opaque dec1 : Nat → Nat
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axiom dec1_lt (n : Nat) : dec1 n < n
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opaque dec2 : Nat → Nat
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axiom dec2_lt (n : Nat) : dec2 n < n
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def foo (n : Nat) := foo (dec1 n) + bar n
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decreasing_by apply dec1_lt
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where
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bar (m : Nat) : Nat := bar (dec2 m)
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decreasing_by apply dec2_lt
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