source: CGBLisp/tags/rel-1.0-alpha-1/examples/parallelogram.macsyma@ 95

if get('geometry,'version)=false then load(geometry);
ginit();

gpoints(A,B,C,D,M1,M2,P,Q,R); /* Declare points */
garbitrary(A,B,C); /* Declare arbitrary points */

/* Geometrical hypotheses */
parallel(A,B,C,D);
parallel(A,C,B,D);
midpoint(M1,A,C);
midpoint(M2,B,D);
ghypot();

/* Geometrical conclusions */
identical(M1,M2);
gconcl();

/* Generate ideal */
gideal();