... inthe larger context of component-based programming. Because of message-passingconcurrency we no longer have the limitations of the synchronous “lock-step”execution of Chapter 4. We first introduce ... tuples:area({square, Side}) -& gt;Side*Side;area({rectangle, X, Y}) -& gt;X*Y;area({circle, Radius}) -& gt;3. 141 59*Radius*Radius;area({triangle, A, B, C}) -& gt;S=(A+B+C)/2;math:sqrt(S*(S-A)*(S-B)*(S-C)).This ... operation of the hypothetical lift control system of a build-ing, with a fixed number of lifts, a fixed number of floors between which liftstravel, and users. Figure 5 .4 gives an abstract view of what...