Hi Maria, > can i ask what you mean by a 'mathematical alphabet'? The alphabet is Σ Σ = {a,b,l,m,r,w,s,p,n} * a = prefix marker * b = signbox marker * l = left lane marker * m = middle lane marker * r = right lane marker * w = writing symbol * s = sequential symbol * p = punctuation symbol * n = number token Section 4 of the Modern SignWriting specification deals with the mathematical model. More in depth reading is available on Wikipedia under formal language theory. http://en.wikipedia.org/wiki/Formal_language > does this mean that the same number of variations > apply to all symbols - or something like that? There is part of that. Every base symbol has a specific number of valid fills and rotations. If symbols are variations of other symbols, then they all have the same valid fills and rotations. > wow - it is wonderful to hear about configuring the ISWA 2010 for easy > sub-sets or for more complex custom sub-sets! So in theory each language > could have his own symbol-set in Puddle? Yes, the easy configuration is easy. The more complex custom sub-sets are theory only. > If you would ever like to use the LSM Puddle with results from this small > section of my work about base symbols as a dummy experiment..please just > ask, i hope to complete this section soon. Excellent. I'll keep you informed. Regards, -Steve