Concurrent processes

Concurrency is a field in computer science concerned with processes that run at the same

time $($concurrently$).$ A fundamental principle in concurrency is that two processes can't

write different data to the same place at the same time $-$ this is called a race condition.

When a race condition occurs, we can't be sure what state the written data is in$.$

On a computer, a process typically consists of a sequence of steps to be executed one

after the other. A process runs on a clock, with one step being executed every clock cycle.

In the following, we take a clock cycle to be one millisecond. We consider the situation

where a process repeats immediately after it is finished.

Task $5(2$ Marks$).$ Suppose a process has the following steps.

What step will the process be executing after $23$ milliseconds?

Write down a congruence that explains this fact.