349da6cae2
This PR improves the usability of the `[grind =]` attribute by
automatically handling
forbidden pattern symbols. For example, consider the following theorem
tagged with this attribute:
```
getLast?_eq_some_iff {xs : List α} {a : α} : xs.getLast? = some a ↔ ∃ ys, xs = ys ++ [a]
```
Here, the selected pattern is `xs.getLast? = some a`, but `Eq` is a
forbidden pattern symbol.
Instead of producing an error, this function converts the pattern into a
multi-pattern,
allowing the attribute to be used conveniently.
22 lines
734 B
Text
22 lines
734 B
Text
attribute [grind] List.append_ne_nil_of_left_ne_nil
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attribute [grind] List.append_ne_nil_of_right_ne_nil
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/--
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info: [grind.ematch.pattern] List.getLast?_eq_some_iff: [@List.getLast? #2 #1, @some ? #0]
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-/
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#guard_msgs (info) in
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set_option trace.grind.ematch.pattern true in
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attribute [grind =] List.getLast?_eq_some_iff
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/--
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info: [grind.assert] xs.getLast? = b?
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[grind.assert] b? = some 10
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[grind.assert] xs = []
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[grind.assert] (xs.getLast? = some 10) = ∃ ys, xs = ys ++ [10]
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[grind.assert] xs = w ++ [10]
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[grind.assert] ¬w = [] → ¬w ++ [10] = []
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[grind.assert] ¬w ++ [10] = []
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-/
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#guard_msgs (info) in
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set_option trace.grind.assert true in
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example (xs : List Nat) : xs.getLast? = b? → b? = some 10 → xs ≠ [] := by
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grind
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