Question about a notation in Practical Programming

[CommanderFun]

Short question: when something like an assistance exercise is written in a program as "3-5x10-12" does this indicate a set/rep progression scheme? Like starting with 3 sets of 10, then the next session 3 sets of 11, and finally after 3 sets of 12 moving up to 4 sets of 10 and working the reps up again? Or is this just to indicate taking your pick of sets/reps within a certain range?

[Hayden-William Courtland]

Either approach can work.