My girlfriend showed me dimensions in LaTeX documents typeset like this : \hspace{1,5cm}
instead of what I would have thought was the correct \hspace{1.5cm}
(we are french).
It seems that both syntaxes are understood by TeX and LaTeX engines even without internationalization packages.
Can you explain to me why it is so ? Did D. Knuth thought about this at the very beginning of is project, or is this more recent ?
Thanks for any pointer.
\bye