public Object toPrefix() {
Object r = Lisp.list(coef[coef.length - 1].toPrefix());
Object x = var.toPrefix();
for (int i = coef.length - 1; i > 0; i--) {
r = Lisp.list(Lisp.cons("*", Lisp.cons(x, r)));
if (!coef[i - 1].equals(Zahl.ZERO)) {
r = Lisp.list(Lisp.cons("+", Lisp.cons(coef[i - 1].toPrefix(), r)));
}
}
return Lisp.car(r);
}
