Church–Turing thesis what can be computed is invalid". They claim that forms of computation not captured by the thesis are relevant today, terms which they call super-Turing computation. Philosophers have interpreted the Church–Turing thesis as having implications for the philosophy of mind. B. Jack Copeland states that it is an open empirical question whether there are actual deterministic physical processes that, in the long run, elude simulation by a Turing machine; furthermore, he states that it is an open empirical question whether any such processes are involved in the working of the human brain. There are also some important open questions which
Turing completeness one instruction set computer) and the ability to change an arbitrary amount of memory ("e.g.", the ability to maintain an arbitrary number of data items). Of course, no physical system can have infinite memory; but if the limitation of finite memory is ignored, most programming languages are otherwise Turing complete. In colloquial usage, the terms "Turing complete" or "Turing equivalent" are used to mean that any real-world general-purpose computer or computer language can approximately simulate the computational aspects of any other real-world general-purpose computer or computer language. Real computers constructed so far can be functionally analyzed like a single-tape Turing