Dear All, I made a bit of housekeeping work in inifcns.cpp: 1) Make abs_power aware on even powers, even if they are not numeric. 2) Add several hold() to returns, which cannot be processed further. I shall admit, that this can be misdone, so please check. Best wishes, Vladimir -- Vladimir V. Kisil email: kisilv@maths.leeds.ac.uk www: http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://www.worldscientific.com/worldscibooks/10.1142/p835