# Cortex language 3A

Cortex language 3A is an esolang by User:PythonshellDebugwindow that follows the specifications of a Cortex language 3.

## Memory model

Cortex language 3A uses a tape of 16 arbitrary-size unsigned integers. The current cell is the cell pointed to by the cell pointer. The cell pointer wraps around the tape.

## Syntax

Same as brainfuck, e.g. each character is its own command that takes no arguments and returns no value. The one exception to this rule is the ; command, whose result depends on the following character(s).

## Commands

Command Effect
& Increment the current cell
' If the current cell is zero, jump to the matching :
* Square the current cell
~ Increment the cell pointer
\$ Decrement the current cell (raises an error if cell == 0)
: If the current cell is nonzero, jump back to the matching '
[ Output the Unicode character of the current cell
] Input an unsigned base-3 integer to the current cell
; Depends on the next instruction:
Command After Popular problem to run
& Print "Hello, World!" exactly like that
' Truth-machine
* ROT13 encode/decode user input
~ Nth number in the Fibonacci sequence where N = base 10 user input
\$ Interpret brainfuck where the program is inputted by the user
: Interpret Deadfish where the program is inputted by the user
[ Bootstrap for program = user input
] FizzBuzz until 100
; Depends on the next instruction:
Command After Popular problem to run
& Cat program
' 99 bottles of beer
* Factorial of base 10 input number
~ Digital root of base 10 input number
\$ Infinite loop
: Run a looping counter from 0 to infinity
[ Mandelbrot set
] Disan Count for base 10 input number
; Fibonacci sequence

All others are ignored. Sequences like ;X and ;;X are also ignored.

## Examples

;&
;'

Cat:

;;&

ROT13 encoder/decoder for user input:

;*

And so on.

## Turing-completeness

Through prime factorization of the tape, as well as unbounded looping using ' and :, Cortex language 3A is Turing-complete.