If I enter
expr1: sum(a[i]*x^i,i,1,inf)+sum(c[i]*x^i,i,1,inf);
then sumcontract will pull everything inside one sum.
If I enter
expr2: A*sum(a[i]*x^i,i,1,inf)+B*sum(c[i]*x^i,i,1,inf);
then sumcontract has no effect.
I want to work with infinite series and this is making things harder. I can get what I want another way. I can change the sum to a finite series with N = 20 lets say and then use say
expr2: A*sum(a[i]*x^i,i,1,inf)+B*sum(c[i]*x^i,i,1,20);
sum(ratcoeff(expr2,x,i)*x^i,i,1,20);
but that is not really as easy to work with.
Is there any way to pull the factors A and B inside a single sum and keep the infinity.
Rich