File extension problem under KDE
sorry for the stupid question,
but I have a problem and haven't found any solution to it on this forum so far.
The problem is how to recognize different file types under KDE.
I have Mathematica files (with extension .nb and plain text format).
I want them to be opened with Mathematica.
I try to edit them as [Right-click]Properties>Settings>... and choose Filename patterns *.nb *.NB to be declared as Mathematica notebooks and opened with Mathematica. But after this all the plain text files (.txt, .cpp, .h ) are opened with Mathematica. When I declare these (.txt, .cpp, .h ) to be opened with KWrite, Mathematica notebooks are also opened with KWrite.
How is it possible to make KDE aware of the new filetypes ?
Thanks in advance,
PS: Below are the first few lines of .nb-file if this might help:
(************** Content-type: application/mathematica **************