We will call a computation monotonic if it deals exclusively with monotonic structures
The great advantage of monotonic computational systems is that the order in which the operations of the system are carried out does not affect the result of the computation. In other words, we do not have to worry about the order; neither do we have to clutter the description of the computation with details about order.
For example if I execute a-b-c I get a different result from b-a-c. On the other hand if I try to compute consistent values for X and Y using the logical equalities d & e & f it is impossible no matter what order I choose.
(a) X := 1 (d) X = 1 (b) X := 2 (e) X = 2 (c) Y := X*2 (f) Y = X*2