Could a computer theoretically compute all integrals in terms of some special functions or there need to be exist infinite number of such special functions to represent all integrals?
I know there theoretically could be exist a computer to prove all elementary geometry theorem.
What is so special about special functions? They are functions that someone thought was special enough to give it a name. For example the gamma function is nothing special (at first glance). That being said, special functions are an "open set", so we can just define new special functions if needed and then any function can be represented as a special function.
$$\Xi (x;t) = \sum_{i=0}^t \int_0^x \Gamma(t)dt$$
I call this the Xi special function.....