ok, I see. A problem with LyX. Write into the preamble:
\newtheorem{theorem}{FrenchTheorem} \let\thm\theorem
It works almost perfectly. Without inserting "\let\thm\theorem" in the
preamble, the output DVI file displays "Theorem 0.1" whereas otherwise it
appears "FrenchTheorem 1.". It seems that anything was changed in the
theorem numbering.
change the first line to
\newtheorem{theorem}{FrenchTheorem}[section]
Could not I have the French label for Theorem in the DVI file by appropriately changing the amsmaths.inc file? If so, where should I operate the change? I can change the label for definitions, corollaries, and so on... but for theorem I do not know how to do it.
Thank you a lot in advance!
Paul
