1d66ff8231
Fixes a long-standing bug in the the `sorryAx` app unexpander that prevented it from applying. Now `sorry` pretty prints as `sorry`.
50 lines
1.5 KiB
Text
50 lines
1.5 KiB
Text
def Vect (n: Nat) (A: Type u) := {l: List A // l.length = n}
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def Vect.cons (a: A) (v: Vect n A): Vect (n + 1) A :=
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⟨a::v.val, by simp [v.property]⟩
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instance: GetElem (Vect n A) Nat A (λ _ i => i < n) where
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getElem vec i _ := match vec with | ⟨l, _⟩ => l[i]
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set_option pp.mvars false
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/--
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error: type mismatch
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xm[i]
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has type
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Vect m A : outParam (Type _)
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but is expected to have type
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A : outParam (Type _)
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---
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error: type mismatch, term
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ih
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after simplification has type
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i < as.length : Prop
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but is expected to have type
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?_ : Type _
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---
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error: failed to prove index is valid, possible solutions:
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- Use `have`-expressions to prove the index is valid
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- Use `a[i]!` notation instead, runtime check is performed, and 'Panic' error message is produced if index is not valid
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- Use `a[i]?` notation instead, result is an `Option` type
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- Use `a[i]'h` notation instead, where `h` is a proof that index is valid
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A : Type _
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m i j : Nat
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as : List A
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xm : List (Vect m A)
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h0 : xm.length = as.length
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ih : i < (List.zipWith cons as xm).length
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jh : j < m
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⊢ ?_ sorry j
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-/
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#guard_msgs in
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theorem Vect.aux
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{as: List A} {xm: List (Vect m A)}
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(h0: xm.length = as.length)
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(ih: i < (List.zipWith cons as xm).length)
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(jh: j < m)
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: ((List.zipWith cons as xm)[i])[j + 1] =
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xm[i]'(by simpa[h0] using ih)[j] := by
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-- Correct syntax requires an extra pair of parentheses:
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-- (xm[i]'(by simpa[h0] using ih))[j]
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-- but `lean` should not crash.
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sorry
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