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RE: Blockchain Technology Comprehension. A Survey On Distributed Systems -Part 2

Hey bro! It's nice to know you are serious with this project, I really liked your post.
There is something that's not clear to me, you define concurrent programs as a multiple thread program. I imagine that like many programs executing itselves and interacting with each other, but if that's so, then you can count the states of a concurrent program as the sum of several sequential program states. Since sequential programs have a finite set of states then the sum of the states of a finite set of sequential programs is finite. But then why concurrent programs have infinite states, that's my doubt

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I'm happy to know that you liked the post.

Ok, let's clarify it a little bit.
  1. The threads are series of instructions (a.k.a. statements) executed when running a program. The state is the current situation of the variables stored in memory by the program.
  2. A program can be determined by the set of operations allowed for that particular program and its initial state (much like how you determine the position of a body at any time if you know the position at t0 and the explicit expression of the function V(t) in classical mechanics).
  3. Changes on states of a program are the result of applying an atomic operation from (Aπ) to the previous state. For the initial execution the first operation is made on the initial state, then the second operation is executed over the result of the first operation and so on.
  4. The execution of any program (not just concurrent ones) can be thought of as a infinite series of states. Even if a program state is constant, it can be represented as an infinite series of the initial state σ = S0S0S0...
    So there is no such a finite series for a sequential program for a given execution. What do exist is a finite sequence for a partial execution of a program, this fact does not change if the program is sequential or concurrent.

I hope I have given a clearer explanation. If you have more questions make more comments without doubt.

cya.