Dear All, Please find a patch to prevent crashes described in: https://www.ginac.de/pipermail/ginac-list/2020-June/002304.html Best wishes, Vladimir -- Vladimir V. Kisil http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://goo.gl/EaG2Vu Software: Geometry of cycles http://moebinv.sourceforge.net/ Jupyter: https://github.com/vvkisil/MoebInv-notebooks