Question: What is wrong that the command solve does not display an answer

Good day, all.

Please, I am working on the following code but found out that the command solve is not displaying any result. Your assistance and suggestions would be appreciated. Thank you, and best regards.

restart;
NULL;
t := sum(a[j]*q^j, j = 0 .. 9);
H := diff(t, q);
F := diff(t, q $ 2);
p1 := simplify(eval(t, q = x)) = y[n];
p2 := simplify(eval(F, q = x)) = f[n];
p3 := simplify(eval(F, q = x + h/4)) = f[n + 1/4];
p4 := simplify(eval(F, q = x + h/2)) = f[n + 1/2];
p5 := simplify(eval(F, q = x + (3*h)/4)) = f[n + 3/4];
p6 := simplify(eval(F, q = x + h)) = f[n + 1];
p7 := simplify(eval(F, q = x + (5*h)/4)) = f[n + 5/4];
p8 := simplify(eval(F, q = x + (3*h)/2)) = f[n + 3/2];
p9 := simplify(eval(F, q = x + (7*h)/4)) = f[n + 7/4];
p10 := simplify(eval(F, q = x + 2*h)) = f[n + 2];
r := seq(a[i], i = 0 .. 9);
s := p || (1 .. 10);

solve({s}, {r});