Our current understanding

- The system, T, is the abstract machine to which the programming language is the interface.
  - I.e., it is an amalgam of compiler, hardware and memory manager
- The conceptual model C(T) is the mental model of that abstract machine held by experienced programmers. For example, it includes—
  - memory allocation and an awareness of the stack, the heap and static storage.
  - expression parsing
  - structured data
  and it has multiple connected levels of abstraction