# How to expand an symbolic expression.

With Maple I can write

```
T := proc(f,n,x)
local v;
add(binomial(n,v)*f(v+1)*(x)^v,v=0..n)
end:
```

and then

```
T(f,4,x)
```

will give me the answer

```
f(1)+4*f(2)*x+6*f(3)*x^2+4*f(4)*x^3+f(5)*x^4.
```

If I write the same with Sage

```
def T(f,n,x):
return add(binomial(n,v)*f(v+1)*(x)^v for v in (0..n))
var('f')
T(f,4,x)
```

then I will get the answer

```
5*x^4 + 16*x^3 + 18*x^2 + 8*x + 1.
```

How do I have to proceed to get Maple's answer?

The answer, as indicated by burcin, simply is: Replace in your code "var('f')" by "f=function('f')".