5 If Louis Reasoner implements the squarer with a multiplier, like this:
10 let us see how we will use it.
12 (define a (make-connector))
13 (define b (make-connector))
15 (set-value! a 10 'user)
17 At this point, we expect b to have the value 100. Indeed it is. Now, instead
18 we set the value of b to be 400. But multiplier needs two values to operate.
19 We have set only b. So, the contraint never propagates to a. Here is the
20 output of a repl session:
22 > (set-value! e 400 'user)
24 Probe: squarer output = 400