// symbols.
	for _, rightTerm := range e.Right {
		op := rightTerm.Op
		rval, rerr := rightTerm.Right.evalNode(r, tableAlias)
		if rerr != nil {
			return nil, rerr
		}
		err := lval.arithOp(op, rval)
		if err != nil {
			return nil, err
		}
	}
	return lval, nil
}

func (e *MultOp) evalNode(r Record, tableAlias string) (*Value, error) {
	lval, lerr := e.Left.evalNode(r, tableAlias)

	opModulo   = "%"
)

// For arithmetic operations, if both values are numeric then the
// operation shall succeed. If the types are unknown automatic type
// conversion to a number is attempted.
func (v *Value) arithOp(op string, a *Value) error {
	err := inferTypeForArithOp(v)
	if err != nil {
		return err
	}

	err = inferTypeForArithOp(a)
	if err != nil {
		return err
	}