2ffd929227
The constraints don't need to be in the same universe anymore. The new test demonstrates why this is useful.
42 lines
827 B
Text
42 lines
827 B
Text
structure Magma.{u} where
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α : Type u
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mul : α → α → α
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def Nat.Magma : Magma where
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α := Nat
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mul a b := a * b
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def Prod.Magma (m : Magma.{u}) (n : Magma.{v}) : Magma where
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α := m.α × n.α
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mul | (a₁, b₁), (a₂, b₂) => (m.mul a₁ a₂, n.mul b₁ b₂)
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instance : CoeSort Magma.{u} (Type u) where
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coe m := m.α
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def mul {s : Magma} (a b : s) : s :=
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s.mul a b
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unif_hint (s : Magma) where
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s =?= Nat.Magma |- s.α =?= Nat
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unif_hint (s : Magma) (m : Magma) (n : Magma) (β : Type u) (δ : Type v) where
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m.α =?= β
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n.α =?= δ
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s =?= Prod.Magma m n
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s.α =?= β × δ
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def f1 (x : Nat) : Nat :=
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mul x x
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#eval f1 10
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def f2 (x y : Nat) : Nat × Nat :=
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mul (x, y) (x, y)
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#eval f2 10 20
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def f3 (x y : Nat) : Nat × Nat × Nat :=
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mul (x, y, y) (x, y, y)
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#eval f3 7 24
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