- It can move the tape one square to the left.
- It can move the tape one square to the right.
- It can erase a 0 and print a 1.
- It can erase a 1 and print a 0.
Here’s where the analogy with logic comes in. Instead of logic’s rules of inference, we have a set of rules of the form “under condition C perform act A”. Rules such as "under condition C perform act A" are called the computer programme. And the purpose of the programme is to encode information. This information is encoded in the binary code of zeroes and ones.
- Programs are entirely syntactical.
- Minds have a semantics.
- Syntax is not the same as, nor by itself sufficient for, semantics.