No. 1 in quest 1, part 3, rules, is Zach. Let’s take a look.

Several interesting features:

1. The character > is used to keep track of an intermediate stage. The dark red head stays on the string and the >, the yellow head moves up and down.
2. There’s a blue head at the end of the string. Sometimes a character is added there at the end. Like, do some processing now, delay some processing until the end. (C at the start of the string adds a B at the end, D at the start adds a C at the end.)
3. Sometimes P’s are written and then deleted. Right when a > is deleted and both dark red and yellow and one more move right, then 2 P’s are deleted. In general, P’s are written by green and purple and deleted by blue and red. Writing left and up.

Code .