Fair and unfair schedules

[fintara]

I cannot understand what fairness means in this context. I think it must be related to the fact that the systematic exploring always uses random steps.

There is an option in p check that can control the max steps, and the default is 10,000 unfair and 100,000 fair steps - what does it imply? Does it mean each schedule has at most 110,000 steps overall? And a step is one action (send, receive, goto) or this isn't true?

There is also PCT and Fair PCT scheduling strategies, where fairness is not described in the PCT paper.

Any help is appreciated! 🙏