17 lines
573 B
Text
17 lines
573 B
Text
reset_grind_attrs%
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set_option grind.warning false
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attribute [grind] List.not_mem_nil
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/--
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error: tactic 'grind' failed, the goal mentions the declaration `incList`, which is being defined. To avoid circular reasoning, try rewriting the goal to eliminate `incList` before using `grind`.
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as✝ : List Nat
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a : Nat
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as : List Nat
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⊢ ∀ (a : Nat), a ∈ (incList as).val → a > 0
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-/
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#guard_msgs (error) in
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def incList (as : List Nat) : { as : List Nat // ∀ a, a ∈ as → a > 0 } :=
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match as with
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| [] => ⟨[], by grind⟩
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| a::as => ⟨(incList as).1, by grind⟩
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