/* tetraquad_int.h  1 <= n <=6 at this time                           */
/*                  nn returned is n*n                                */
/*                  integral = sum i=0 to nn-1 W[i]*f(X[i],Y[i],Z[i]) */

int tetraquad_int(int n, double x1, double y1, double z1,
		         double x2, double y2, double z2,
	                 double x3, double y3, double z3,
		         double x4, double y4, double z4,
                         double X[], double y[], double Z[], double W[]);