# crefthe — cross referencing with proper definite articles and declensions
"crefthe" is a LaTeX package aimed at helping `\cref` to handle the definite articles and declensions properly (especially for the phenomenon of article contractions in many European languages, such as French and German).
## Motivation
By default, when using cleveref's `\cref` to reference theorem-like environments, the names do not contain definite articles. This may be acceptable for English, but certainly not good enough for languages such as French, Italian, Portuguese, Spanish, etc. — in these cases there shall be grammatical errors and would give you a strong feeling that it is machine-generated.
As an example, if we define the French names to be:
```latex
\crefname{theorem}{le théorème}{les théorèmes}
\crefname{proposition}{la proposition}{les propositions}
```
Then when one writes (which means "*We can deduce this from ...*"):
```latex
On peut le déduire de \cref{thm1,thm2,prop3}.
```
the result would be:
> On peut le déduire **de les** théorèmes 1 et 2 et **la** proposition 3.
which is wrong, as the correct result should be:
> On peut le déduire **des** théorèmes 1 et 2 et **de la** proposition 3.
`\cref` would not be able to handle such cases correctly.
### The solution
Thus, it would be better to have a new command `\crefthe[]{}`, and to use it like
```latex
\crefthe[de]{thm1,thm2,prop3}
```
in order to get "*des théorèmes 1 et 2 et de la proposition 3*".
## Usage
Simply load the package with:
```latex
\usepackage{crefthe}
```
> "crefthe" uses "cleveref" internally, thus it should usually be placed at the last of your preamble.
> With the package option `overwrite`, you may simply use `\cref` for `\crefthe`, and similarly for other commands.
Before everything, you need to define the names, which can be done with `\crefthename`. Its syntax is similar to `\crefname`, but now you can specify the definite articles, for example (in French):
```latex
\crefthename{theorem}[le]{théorème}[les]{théorèmes}
```
Then you can use the command `\crefthe` as follows:
- `\crefthe[]{}`
- This will pass the preposition `` to the definite articles that follows. Its behavior depends on the current language (for example, in Spanish, `` is passed only to the first definite article, while in French it is passed to everyone).
- `\crefthe-[]{}` and `\crefthe+[]{}`
- In case the automatic version does not meet your needs, here are two manual ones. The `-` version passes the preposition `` only to the first definite article, while the `+` version passes `` to every definite article.
> - There is also a stared version `\crefthe*` for generating the same text but without hyperlinks.
> - The name-only relatives are also available: `\namecrefthe` and `\namecrefsthe`.
> - `\cpagerefthe` and `\Cpagerefthe` are provided as well.
### Regarding language with declensions
In German, there are four declensions: nominative (`Nominativ`), genitive (`Genitiv`), dative (`Dativ`) and accusative (`Akkusativ`). For such situation, we introduce the command `\crefthevariantname` to specify the referencing name for the correspond environment. Below is an example of usage:
```latex
\crefthevariantname{theorem}
{
{Satz}{Sätze}
, Nominativ = [der]{Satz}[die]{Sätze}
, Genitiv = [des]{Satzes}[der]{Sätze}
, Dativ = [dem]{Satz}[den]{Sätzen}
, Akkusativ = [den]{Satz}[die]{Sätze}
}
```
The first line in the configuration is the default set of names when no variant is specified. It is recommended, though not required.
After this, you may refer to a theorem via
```latex
\crefthe[,variant=]{