This PR adds support for `Int.sign`, `Int.fdiv`, `Int.tdiv`, `Int.fmod`,
`Int.tmod`, and `Int.bmod` to `grind`. These operations are just
preprocessed away. We assume that they are not very common in practice.
Examples:
```lean
example {x y : Int} : y = 0 → (x.fdiv y) = 0 := by grind
example {x y : Int} : y = 0 → (x.tdiv y) = 0 := by grind
example {x y : Int} : y = 0 → (x.fmod y) = x := by grind
example {x y : Int} : y = 1 → (x.fdiv (2 - y)) = x := by grind
example {x : Int} : x > 0 → x.sign = 1 := by grind
example {x : Int} : x < 0 → x.sign = -1 := by grind
example {x y : Int} : x.sign = 0 → x*y = 0 := by grind
```
See #11622
Hi, these are just some spelling corrections.
There is one I wasn't completely sure about in
src/Init/Data/List/Lemmas.lean:
> See also
> ...
> Also
> \* \`Init.Data.List.Monadic\` for **addiation** _(additional?)_ lemmas
about \`List.mapM\` and \`List.forM\`
This PR ensures users can select the "minimal indexable subexpression"
condition in `grind` parameters. Example, they can now write `grind [!
-> thmName]`. `grind?` will include the `!` modifier whenever users had
used `@[grind!]`. This PR also fixes a missing case in the new pattern
inference procedure.
It also adjusts some `grind` annotations and tests in preparation for
setting the new pattern inference heuristic as the new default.
This PR moves `String.utf8EncodeChar` to the prelude to prepare for the
imminent redefinition of `String`.
The definition in the prelude uses modulo and division operations on
natural numbers. In `String.Extra`, a `csimp` lemma is provided, showing
that the new definition is equal to the previous one (which is now
called `utf8EncodeCharFast`) which uses bitwise operations on `UInt8`.
This PR eliminates uses of `intros x y z` (with arguments) and updates
the `intros` docstring to suggest that `intro x y z` should be used
instead. The `intros` tactic is historical, and can be traced all the
way back to Lean 2, when `intro` could only introduce a single
hypothesis. Since 2020, the `intro` tactic has superceded it. The
`intros` tactic (without arguments) is currently still useful.
This PR tries to improve the E-matching pattern inference for `grind`.
That said, we still need better tools for annotating and maintaining
`grind` annotations in libraries.
closes#9125
