public static vCset Cset(int low, int high) { if (low == high) { return cslist[low]; } else { return new vCset(low, high); }
public static vCset Cset(int c) { return cslist[c];
public static vCset Cset(int low, int high) {    if (low == high) {	return cslist[low];    } else {	return new vCset(low, high);    }}