11 lines
563 B
Text
11 lines
563 B
Text
def Int.leastOfBdd {P : Int → Prop} [DecidablePred P] (b : Int) (Hb : ∀ z : Int, P z → b ≤ z)
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(Hinh : ∃ z : Int, P z) : { lb : Int // P lb ∧ ∀ z : Int, P z → lb ≤ z } :=
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sorry
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theorem Int.coe_leastOfBdd_eq {P : Int → Prop} [DecidablePred P] {b b' : Int} (Hb : ∀ z : Int, P z → b ≤ z)
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(Hb' : ∀ z : Int, P z → b' ≤ z) (Hinh : ∃ z : Int, P z) :
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(leastOfBdd b Hb Hinh : Int) = leastOfBdd b' Hb' Hinh := by
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grind
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example (f : Int → Int) (x y : Int) : x ≤ y → y ≤ x → f x = f y := by
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grind -lia -linarith
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