A minimal stack based language using reverse polish notation.

• Arithmetic operations: + - * / %
• Control flow: loops and conditionals

• [Arithmetic]: consumes two numbers and adds the result on the stack 4 1 - -> [3]
• [number]: add a number to the stack
• dup: duplicate top of stack
• swap: swap top two of the stack
• drop: drop top of stack
• print: print top of stack (consumes top of stack)
• if-[cmp] ... else ... end-if: consumes top two of stack for comparison and executes left or right based on result.
• loop-[cmp] ... end-loop: consumes top two of stack before each loop for comparison
• proc:[name] ... end-proc: defines a procedure, it can be called using [name]
• [cmp]: can be one of eq,neq,lt,gt,leq,geq

even number in the first 20

first 20 squares