case VSPACE_G_DAY : int x = XSDFuncOp.compareDateTime(nv1, nv2) ; if ( x == Expr.CMP_INDETERMINATE ) throw new ExprNotComparableException("Indeterminate dateTime comparison") ;
case VSPACE_G_YEARMONTH : int x = XSDFuncOp.compareDateTime(nv1, nv2) ; if ( x != Expr.CMP_INDETERMINATE ) return x ;