Let A be a set of polynomials with real coefficients and let them satisfy the following conditions:(i) if f∈A and deg(f)≤1, then f(x)=x−1;(ii) if f∈A and deg(f)≥2, then either there exists g∈A such that f(x)=x2+deg(g)+xg(x)−1 or there exist g,h∈A such that f(x)=x1+deg(g)g(x)+h(x);(iii) for every g,h∈A, both x2+deg(g)+xg(x)−1 and x1+deg(g)g(x)+h(x) belong to A.Let Rn(f) be the remainder of the Euclidean division of the polynomial f(x) by xn. Prove that for all f∈A and for all natural numbers n≥1 we have Rn(f)(1)≤0, and that if Rn(f)(1)=0 then Rn(f)∈A.