* dongen <[log in to unmask]> [2012-02-02 13:18:44 +0000]: Dear Bruno, : Now here is the question. What I'd like to know if there's an easy way : for a substitution of the form : a[expression] -> \csname myA[expression]\endcsname : If there is an easy way to do this than this simply lets me apply the : substitution to the guard expressions and they then give me the conditions : that need to be satisfied before I can return the ``result'' (the text : between the = and the |). Of course, I also have to make the substitution : in the result. I think I've solved the problem, so I probably won't need to know about the substitution. If the answer is easy, I'd still like to know. Otherwise, please forget about it. Regards, Marc van Dongen