d2853ecbc4
This PR removes unnecessary parameters from the funcion induction principles. This is a breaking change; broken code can typically be adjusted simply by passing fewer parameters. Part 1, before stage0 update. Closes #6320
23 lines
840 B
Text
23 lines
840 B
Text
inductive Many (α : Type u) where
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| none : Many α
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| more : α → (Unit → Many α) → Many α
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def many_map {α β : Type} (f : α → β) : Many α → Many β
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| .none => .none
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| .more x xs => Many.more (f x) (fun () => many_map f <| xs ())
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/--
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info: many_map.induct {α : Type} (motive : Many α → Prop) (case1 : motive Many.none)
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(case2 : ∀ (x : α) (xs : Unit → Many α), motive (xs ()) → motive (Many.more x xs)) (a✝ : Many α) : motive a✝
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-/
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#guard_msgs in
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#check many_map.induct
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-- Unrelated, but for fun, show that we get the identical theorem from well-founded recursion
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def many_map' {α β : Type} (f : α → β) : Many α → Many β
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| .none => .none
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| .more x xs => Many.more (f x) (fun () => many_map' f <| xs ())
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termination_by m => m
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example : @many_map.induct = @many_map'.induct := rfl
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