please urgent

Consider the computer program shown in Figure 1. Normally, the instructions would be processed sequentially-first, A=1, then B=2, and so on. However, notice that there is no logical reason that prevents the first three instructions- A=1;B=2;C=3-from being processed in any order or concurrently. With the continuing decline of the cost of computer hardware, and processors in particular, there is increasing interest in concurrent processing to achieve greater speed and efficiency. The use of Petri nets, graph models of concurrent processing, is one method of modeling and studying concurrent processing. FIGURE 1: A COMPUTER PROGRAM In Figure 2, we have modelled the computer program of Figure 1. Here the events (transitions) are the instructions, and the places represent the conditions under which an instruction can be executed. 1. Write down the transitions(1x6) 2. Differentiate between tokens vs. places. What is the significance of tokens? (4 marks) FIGURE 2 PETRINET