Second entry for Geotale; 12 blocks, practical. CT is a variant of the cyclic tag system. Unlike my implementation of FRACTRAN, CT does not rely on numerical precision, and thus is far more practical.
Description of CT: https://esolangs.org/wiki/Bitwise_Cyclic_Tag#The_language_CT Example (Collatz Sequence of 3): Initial: 100100100 Program: 010001;100;100100100;;;; Example: Initial: 1 Program: 101;0;;1
