That's right, you need a new version. Get the "Development Snapshot" from the downloads page. Maybe there is a neater or faster way of doing sum, but this seems to do the job: /* sum(vector) - Calculate the sum of all elements in a vector of numbers */ function sum(v, i=0) = len(v) > i ? v[i] + sum(v, i+1) : 0; If the list is empty (or the end of the list is reached), return 0. Else, return the current element plus the sum of the rest of the list. -- View this message in context: http://forum.openscad.org/Unpack-a-vector-tp10350p10377.html Sent from the OpenSCAD mailing list archive at Nabble.com.