ExpressionContext.getInstance().addExpression(new Equality(Numbers.constant("D"), dd));
Expression a = p.getCoefficient(2);
Expression b = p.getCoefficient(1);
Expression c = p.getCoefficient(0);
NaturalNumber two = Naturals.getInstance().create(2);
if (dd instanceof ANumber) {
ANumber d = (ANumber) dd;
if (d.isNegative()) {