Cat has no variables, only instructions which manipulate a stack (e.g. dup, pop, swap), and a special expression form called a quotation (e.g. [1 add]) which pushes an expression onto the stack which can be executed at a later time (e.g. using apply or dip).
For example: 6 7 dup mul sub results in a stack with the value 43 on top.
Last modified 16 December 2024