5f4e6a86d5
This PR updates the formatting of, and adds explanations for, "unknown identifier" errors as well as "failed to infer type" errors for binders and definitions. It attempts to ameliorate some of the confusion encountered in #1592 by modifying the wording of the "header is elaborated before body is processed" note and adding further discussion and examples of this behavior in the corresponding error explanation.
87 lines
1.6 KiB
Text
87 lines
1.6 KiB
Text
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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termination_by (i + j, 0)
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decreasing_by
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· apply Prod.Lex.left
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apply Nat.lt_succ_self
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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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termination_by (i + j, 1)
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decreasing_by
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· apply Prod.Lex.right
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decide
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· apply Prod.Lex.left
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apply Nat.lt_succ_self
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end
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/-- info: g.eq_1 (i : Nat) : g i Nat.zero = if i < 5 then 0 else 1 -/
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#guard_msgs in
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#check g.eq_1
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/-- info: g.eq_2 (i j_2 : Nat) : g i j_2.succ = if i < 5 then 0 else h i j_2 -/
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#guard_msgs in
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#check g.eq_2
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/--
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info: g.eq_def (i j : Nat) :
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g i j =
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if i < 5 then 0
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else
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match j with
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| Nat.zero => 1
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| j.succ => h i j
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-/
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#guard_msgs in
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#check g.eq_def
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/-- error: Unknown identifier `g.eq_3` -/
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#guard_msgs in
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#check g.eq_3
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/-- info: h.eq_1 (i : Nat) : h i 0 = g i 0 -/
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#guard_msgs in
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#check h.eq_1
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/-- info: h.eq_2 (i j_2 : Nat) : h i j_2.succ = g i j_2 -/
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#guard_msgs in
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#check h.eq_2
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/--
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info: h.eq_def (i j : Nat) :
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h i j =
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match j with
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| 0 => g i 0
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| j.succ => g i j
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-/
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#guard_msgs in
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#check h.eq_def
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/-- error: Unknown identifier `h.eq_3` -/
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#guard_msgs in
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#check h.eq_3
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/--
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info: g._mutual.eq_def (i : Nat) (x✝ : Nat ⊕' Nat) :
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g._mutual i x✝ =
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PSum.casesOn x✝
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(fun j =>
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if i < 5 then 0
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else
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match j with
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| Nat.zero => 1
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| j.succ => g._mutual i (PSum.inr j))
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fun j =>
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match j with
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| 0 => g._mutual i (PSum.inl 0)
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| j.succ => g._mutual i (PSum.inl j)
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-/
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#guard_msgs in
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#check g._mutual.eq_def
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