It is possible to construct a universal Turing machine because the set of all possible Turing machines is countable, i.e. there is a unique integer for every Turing machine.
It is possible to construct a universal Turing machine because the set of all possible Turing machines is countable, i.e. there is a unique integer for every Turing machine. The integer corresponding to a given Turing machine is called its [blank] number, where [blank] is the name of  this mathematician.
It is possible to construct a universal Turing machine because the set of all possible Turing machines is countable, i.e. there is a unique integer for every Turing machine.
Kurt {Godel}