}
// Test member function el()
for (i=0;i<N;i++) z[i] = 1.0-x[i];
for (i=0;i<N;i++) zz[i] = idx.el(z,i);
localflag = localflag || (maxel(vecsub(vecsub(u,zz),xx)) > sbeps);
globalflag = globalflag || localflag;
if (localflag) {
fail("*** Indexx: Member function el() does not sort inverted array into reverse order");