34bd6e8bfd
This PR improves the error messages produced by the `split` tactic, including suggesting syntax fixes and related tactics with which it might be confused. Note that, to avoid clashing with the new error message styling conventions used in these messages, this PR also updates the formatting of the message produced by `throwTacticEx`. Closes #6224
26 lines
567 B
Text
26 lines
567 B
Text
/-!
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The (attribute-extensible) `rfl` tactic only unfolds the goal with reducible transparency to look
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for a relation which may have a `refl` lemma associated with it. But historically, `rfl` also
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invoked `eq_refl`, which more aggressively unfolds. This checks that this still works.
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-/
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def Foo (a b : Nat) : Prop := a = b
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/--
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error: Tactic `rfl` failed: no @[refl] lemma registered for relation
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Foo
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⊢ Foo 1 1
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-/
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#guard_msgs in
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example : Foo 1 1 := by
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apply_rfl
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#guard_msgs in
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example : Foo 1 1 := by
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eq_refl
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#guard_msgs in
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example : Foo 1 1 := by
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rfl
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