Langton's loops

The "genes" instruct it to make three left turns, completing the loop, which then disconnects from its parent.

Its self-replicating loops are based on one of the simplest elements in Codd's automaton, the periodic emitter.

Langton's Loops run in a CA that has 8 states, and uses the von Neumann neighborhood with rotational symmetry.

The signals travel passively along the wires until they reach the open ends, when the command they carry is executed.

The '70' command advances the end of the wire by one cell, while the '40-40' sequence causes the left turn.

State 6 temporarily joins the genome of the daughter loop and initialises the growing arm at the next corner it reaches.