This is an important fundamental issue that you point out. The library needs to get clear about base OpenSCAD requirements/expectations. As identified, it currently makes use of a list comprehension feature that has been added to OpenSCAD. /I am guessing this issue exists in other parts of the omdl library as well./ Just out of curiosity as I work on an approach to address this issue, what version(s) of OpenSCAD are you using? Have you considered upgrading to a more recent release? Roy -- View this message in context: http://forum.openscad.org/New-site-for-omdl-A-Mechanical-Design-Library-tp20312p21209.html Sent from the OpenSCAD mailing list archive at Nabble.com.