Distributed Shared Memory
When variables are dcelared allread and allwrite, they are in shared memory.
All robots can read and write to allwrite variables and all robots can read from allread
variables. allread variables need to be arrays.
A robot can only write to one element of an allread variable.
Round based Execution
A program will find the first event that satisfies
the precondition, execute it, then start from the top again.