/* ***** This DEMO appears to be broken. Please use the VECT package on the SHARE directory. - JPG 6/5/78 ***** */ /* First, we establish p, q, f, and g as vector entities: */ declare([p, q, f, g], nonscalar); /* To attempt to prove the following vector identity: */ p cross q dotdel f cross g + q cross f dotdel p cross g + f cross p dotdel q cross g = 0; /* Now determine the expansion of: */ laplacian %pi*(s+h) = div 3*s*p;