7.12 In this exercise, you will extend situation calculus to allow for actions that take place simultaneously. You will use a function called Simultaneously, which takes two actions as arguments and denotes the combined action. Consider a grid world containing two agents. Write axioms describing the effects of simultaneous Forward actions:

a. When two agents move at once, unless they are both trying to move to the same location, the result is the same as if one had moved and then the other had moved.

b. If the agents are trying to move to the same location, they remain in place.