[mrcactu5]

beautiful ASCII visualization! In theory class we called it "interval arithmetic"

https://en.wikipedia.org/wiki/Interval_arithmetic (2+2)-free posets, ascent sequences and pattern avoiding permutations https://arxiv.org/abs/0806.0666

[PabloSichert]

Sorry, I couldn't quite follow - could you break it down in simple sentences what the connection between those links you provided and the visualization is?

The coloring depending on response time happens in intervals, that much I can say.

[mrcactu5]

I am not saying anything very deep. We can try to count all the different ways 5 (or 100) people can have sessions on a website

  #1 |--------------------|
  #2        |---------------|      |---------|
  #3   |------------|          |---|
  #4      |----|             |------|      |--|
  #5   |---------------------|

Each of these channels have overlapping event. Some sessions happen strictly before the other. Sometimes, one logs on before the other one logs of. Etc. The more channels we have the more complex behavior. That is all the paper is saying.

Sorry about that.

[PabloSichert]

Thanks for making that example!

Assuming I am looking at your sketch with the x-axis being time, I just want to note that specific to this library there won't be two events (request start, end or log) at the same time. (The "concurrency" here comes from coroutines, not parallel threads)

[mrcactu5]

My mistake. I only see a few outcomes then. #1 happens then #2

  #1 |------|
  #2             |--------|

and #2 happens before #1

  #1                  |-------|
  #2   |---------|

or #1 starts then #2 starts:

  #1   |-------------|
  #2           |------------|

or #1 starts before #2 and finishes before #2

  #1  |---------------------|
  #2       |----------|

For two channels are are 8 possibilities in all. https://oeis.org/A079144