40 lines
792 B
Text
40 lines
792 B
Text
import Lean
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open Lean
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open Lean.Meta
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def tst (declName : Name) : MetaM Unit := do
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IO.println (← getUnfoldEqnFor? declName)
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mutual
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def g (i j : Nat) : Nat :=
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if i < 5 then 0 else
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match j with
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| Nat.zero => 1
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| Nat.succ j => h i j
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def h (i j : Nat) : Nat :=
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match j with
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| 0 => g i 0
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| Nat.succ j => g i j
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end
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termination_by'
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invImage
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(fun
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| PSum.inl n => (n, 0)
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| PSum.inr n => (n, 1))
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(Prod.lex sizeOfWFRel sizeOfWFRel)
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decreasing_by
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simp [invImage, InvImage, Prod.lex, sizeOfWFRel, measure, Nat.lt_wfRel, WellFoundedRelation.rel]
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first
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| apply Prod.Lex.left
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apply Nat.lt_succ_self
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| apply Prod.Lex.right
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decide
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#eval tst ``g
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#check g._eq_1
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#check g._eq_2
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#check g._unfold
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#eval tst ``h
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#check h._eq_1
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#check h._eq_2
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#check h._unfold
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