
// Define a module for the shared variable and processes
module parallel_program {
    var x : int;

    // Initialize x to 0
    init {
        x = 0;
    }

    // Define the actions for LOAD, INC, and STORE
    procedure LOAD() returns (local_x : int) {
        local_x = x;
    }

    procedure INC(local_x : int) returns (new_local_x : int) {
        new_local_x = local_x + 1;
    }

    procedure STORE(new_local_x : int) {
        x = new_local_x;
    }

    // Simulate the parallel execution of P1, P2, and P3
    // This is a simplified representation and would need to be expanded to fully model parallelism
    procedure simulate_parallel() {
        var local_x : int;
        var new_local_x : int;
        var i : int;
        for (i = 1; i <= 30; i = i + 1) {
            local_x = LOAD();
            new_local_x = INC(local_x);
            STORE(new_local_x);
        }
    }

    // Check if there exists an execution that halts with x=2
    invariant check_x_equals_2 : x != 2;

    control {
        // Perform bounded model checking
        v = unroll(30); // Assuming each process increments x 10 times
        check;
        print_results;
        if (!v) {
            // Print counterexample if the property is violated
            print "Counterexample found where x != 2.";
        }
    }
}
