TTDH Function

It is unknown what TTDH(n) really does to n, but all we know from https://www.youtube.com/watch?v=cGRMPUF2RzM&pp=ygUJI2ludHV0bzR1 is that it grows faster than SCG(n), TREE(n), and SSCG(n) but not faster than Tar(n)