Vadim has no issues with the muParser integration. yesterday I was able to compile muparser and build a "hello world example". @Thomas Zecha @andresmmera do you have some ideas how to incorporate it in the code (especially XML import). This functionality enables also the callbacks implementation which has to be done. I attach, as an example, the image of Klayout instance properties window where the value of

R

can be calculated based on `Width, Length, Bends`` .