thanks. didn't see the double instructions until today. it would be better to follow the step by step style of the program and say:
decrease by 1
decrease by 1

instead of "decrease its value by 2" which looks like an instruction call.

dec x should decrease the value in x by one. The example says "decrease by 2" because there are two dec a in a row in the example program.

ISSUE TYPO?:
dec x - decreases the content of the register x by one
=/=
decrease its value by 2,

should "dec" decrease by one or two?