return iNew.String(value.substring(m, n));
return iNew.String(value.substring(m-1, n-1));
vDescriptor Section(vValue i, vValue j) {    int m = this.posEq(i.mkInteger().value);    int n = this.posEq(j.mkInteger().value);    if (m == 0 || n == 0) {    	return null; /*FAIL*/    }    if (m > n) {	return iNew.String(value.substring(n, m));    } else {	return iNew.String(value.substring(m, n));    }}