# What is the purpose of ../ in \input and \include?

I sometimes see `\include{../foo}` and `\input{../bar.tex}` in code examples online.

What does the `../` means? What does it changes? What are its advantages? How is it possible to use it?

• LaTeX and TeX using Unix pathname protocols, even on MSDOS machines. – John Kormylo Mar 21 '19 at 4:20

Let us say you have the following structure:

``````LaTeXFiles (directory)
foo.tex
bar.tex
test (directory)
mwe.tex
``````

Let us say you have the following line in file `mwe.tex`:

``````\include{../foo}
``````

Then the file `foo.tex` in directory `LaTeXFiles` is included. So `../` means: go one directory back.

It simply used the path command available in windows with `cd ..` or `cd test` or `cd LaTeXFiles/test` or simular in unix/linux. Same with line

``````\input{../bar.tex}
``````

It means the file `bar.tex` in directory `LaTeXFiles` is used in file `mwe.tex`.

`../foo` means that the file `foo` is located in the parent of the current working directory (one directory above it).

https://stackoverflow.com/a/23242061

• You could also mention that in TeX this ../ relative syntax has some other beneficial uses such as with the file changed to an additional / e.g. with TeXINPUTS= the use of ..// means the parent all adjoining sibling subfolders and their child folders as well as this folders subfolders – user170109 Mar 20 '19 at 17:42