From the new doc-string:
```quote
In early versions of Lean, the typeclasses provided by `/` and `%`
were defined in terms of `tdiv` and `tmod`, and these were named simply as `div` and `mod`.
However we decided it was better to use `ediv` and `emod`,
as they are consistent with the conventions used in SMTLib, Mathlib,
and often mathematical reasoning is easier with these conventions.
At that time, we did not rename `div` and `mod` to `tdiv` and `tmod` (along with all their lemma).
In September 2024, we decided to do this rename (with deprecations in place),
and later we intend to rename `ediv` and `emod` to `div` and `mod`, as nearly all users will only
ever need to use these functions and their associated lemmas.
```
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