a5b1b8de4f
Offset equalities should not assume default `Nat` instances for numerals, `+`, `*`, and `-` have been used. fixes #755
39 lines
1.2 KiB
Text
39 lines
1.2 KiB
Text
def Additive (α : Type) := α
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instance [OfNat α 1] : OfNat (Additive α) (nat_lit 0) := ⟨(1 : α)⟩
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example : (0 : Nat) = (0 : Additive Nat) := rfl -- Error
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def toA (a : Nat) : Additive Nat := a
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def Foo (α : Type) := α
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instance [OfNat α n] : OfNat (Foo α) n :=
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inferInstanceAs (OfNat α n)
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instance [HAdd α α α] : HMul (Foo α) (Foo α) (Foo α) where
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hMul a b := let a : α := a; let b : α := b; let x : α := a + b; x
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instance [HAdd α α α] : HSub (Foo α) (Foo α) (Foo α) where
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hSub a b := let a : α := a; let b : α := b; let x : α := a + b; x
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instance [HAdd α α α] : HAdd (Foo α) (Foo α) (Foo α) where
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hAdd a b := let a : α := a; let b : α := b; let x : α := a + b + a; x
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example : (2 : Nat) * (3 : Nat) = (2 : Foo Nat) * (3 : Foo Nat) :=
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rfl -- Error
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example : (2 : Nat) + (3 : Nat) = (2 : Foo Nat) + (3 : Foo Nat) :=
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rfl -- Error
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example : (2 : Nat) - (3 : Nat) = (2 : Foo Nat) - (3 : Foo Nat) :=
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rfl -- Error
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example : (2 : Nat) + (3 : Nat) = (2 : Foo Nat) * (3 : Foo Nat) :=
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rfl
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example : (2 : Nat) + (3 : Nat) + (2 : Nat) = (2 : Foo Nat) + (3 : Foo Nat) :=
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rfl
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example : (2 : Nat) + (3 : Nat) = (2 : Foo Nat) - (3 : Foo Nat) :=
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rfl
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