41 lines
639 B
Text
41 lines
639 B
Text
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universe u
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namespace Ex1
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structure A (α : Type u) :=
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(x : α) (f : α → α := λ x => x)
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structure B (α : Type u) extends A α :=
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(y : α := f (f x)) (g : α → α → α := λ x y => f x)
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structure C (α : Type u) extends B α :=
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(z : α := g x y) (x := f z)
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end Ex1
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open Ex1
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def c1 : C Nat := { x := 1 }
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#check { c1 with z := 2 }
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#check { c1 with z := 2 }
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theorem ex1 : { c1 with z := 2 }.z = 2 :=
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rfl
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#check ex1
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theorem ex2 : { c1 with z := 2 }.x = c1.x :=
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rfl
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#check ex2
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def c2 : C (Nat × Nat) := { z := (1, 1) }
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#check { c2 with x.fst := 2 }
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#check { c2 with x.1 := 3 }
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#check show C _ from { c2.toB with .. }
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