Though I have to be honest, I still don’t get what “process P gets processed by G” actually means.
Processes are isolated to each other in the BEAM and communicate via sending messages.
I have not read the paper you linked transitively, as I don’t have the time right now. Perhaps I might be able to do during the weekend, but that’s not a promise.
Thanks a lot. I meant something like this P | G. Process P being parallelised with Process G.
Just spawn them separately then. That makes them running concurrently.
There is no true parallelism in the BEAM.
What do you mean by this? Surely two processes will run in parallel, on different schedulers, if you have more than one CPU core on your system.
By “true parallelism” I mean what I have learned as “parallel computing” at university.
Same operations on different data at the same time. As on GPU or modern CPU using SIMD.
One more reason to make sure we all understand the specific definition of the terms we use in the thread 
Terms like “process”, “encoding”, “parallelism” all have different meanings in different context:
There is no true parallelism within a given BEAM scheduler yes. If you are on a multi-core processor running multiple schedulers (the default) then true parallelism does occur.