RX-wiki

Types of Turing completeness

The definition of a TM doesn’t require looping or recursion, this is what I call “weak” TC. “Self-propelling” TC are machines that do looping or recursion on their own, they don’t need a force (external to the system) that repeatedly applies the transition function.

I coined the terms here

It should be obvious that almost everything (including the universe itself) is (at least) weakly TC (see this and this)

Many people misuse “TC” to refer to BSMs. A BSM is only a finite-memory approximation of a TM, so a BSM is only TC in practice, not theory. However, there’s merit to this comparison.

See also

LBA