37dd26966b
This PR prevents `rcases` and `obtain` from creating absurdly long case tag names when taking single constructor types (like `Exists`) apart. Fixes #6550 The change does not affect `cases` and `induction`, it seems (where the user might be surprised to not address the single goal with a name), because I make the change in Lean/`Meta/Tactic/Induction.lean`, not `Lean/Elab/Tactic/Induction.lean`. Yes, that's confusing.
104 lines
2 KiB
Text
104 lines
2 KiB
Text
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-- This used to have
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-- `case intro.intro.intro.intro.intro.intro.intro.inl`
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/--
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error: unsolved goals
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case inl
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a b c d e f g : Nat
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h : False
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⊢ False
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case inr
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a b c d e f g : Nat
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h : False
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⊢ False
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-/
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#guard_msgs in
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example (h : ∃ a b c d e f g : Nat, False ∨ False) : False := by
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obtain ⟨a, b, c, d, e, f, g, h | h⟩ := h
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/--
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error: unsolved goals
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case inl
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a b c d e f g : Nat
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h : False
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⊢ False
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case inr
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a b c d e f g : Nat
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h : False
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⊢ False
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-/
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#guard_msgs in
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example (h : ∃ a b c d e f g : Nat, False ∨ False) : False := by
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rcases h with ⟨a, b, c, d, e, f, g, h | h⟩
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/--
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error: unsolved goals
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case left.inl
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a b c d e f g : Nat
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h : False
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⊢ False
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case left.inr
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a b c d e f g : Nat
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h : False
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⊢ False
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-/
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#guard_msgs in
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example (h : ∃ a b c d e f g : Nat, False ∨ False) : False ∧ False := by
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constructor
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· obtain ⟨a, b, c, d, e, f, g, h | h⟩ := h
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· sorry
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-- We still get case names for `cases`
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/--
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error: unsolved goals
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case intro
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w✝ : Nat
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h✝ : ∃ b c d e f g, False ∨ False
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⊢ False
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-/
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#guard_msgs in
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example (h : ∃ a b c d e f g : Nat, False ∨ False) : False := by
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cases h
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/--
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error: unsolved goals
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case intro.intro.intro.intro.intro.intro.intro
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a b c d e f g : Nat
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h : False ∨ False
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⊢ False
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-/
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#guard_msgs in
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example (h : ∃ a b c d e f g : Nat, False ∨ False) : False := by
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cases h with | _ a h =>
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cases h with | _ b h =>
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cases h with | _ c h =>
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cases h with | _ d h =>
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cases h with | _ e h =>
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cases h with | intro f h =>
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cases h with | _ g h =>
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skip
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-- And induction
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/--
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error: unsolved goals
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case intro.intro.intro.intro.intro.intro.intro
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a b c d e f g : Nat
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h : False ∨ False
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⊢ False
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-/
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#guard_msgs in
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example (h : ∃ a b c d e f g : Nat, False ∨ False) : False := by
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induction h with | _ a h =>
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induction h with | _ b h =>
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induction h with | _ c h =>
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induction h with | _ d h =>
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induction h with | _ e h =>
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induction h with | intro f h =>
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induction h with | _ g h =>
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skip
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