Input:
`expand(tosum(exp(x)))`
Compute:
$$expand :$$ $$convert\ to\ sum :$$ $$exp(x)$$
Result:
$$1+x+\frac{1}{2}\ x^{2}+\frac{1}{6}\ x^{3}$$
LaTeX:
1+x+\frac{1}{2}\ x^{2}+\frac{1}{6}\ x^{3}
$$expand :$$ $$convert\ to\ sum :$$ $$exp(x) == 1+x+\frac{1}{2}\ x^{2}+\frac{1}{6}\ x^{3}$$