Primitive Domains
Primitive Domain: a set that is fundamental to the application been studied. Its elements are atomic and they are used as answers or semantic outputs e.g. The real number are a primitive domain for mathematicians.
Example:Natural Numbers
Domain Nat = N
Operations
zero:Nat //constant, operation?
one: Nat //constant, operation?
…
plus:Nat x Nat ? Nat
minus:Nat x Nat ? Nat
times:Nat x Nat ? Nat