The reader of this chapter may draw inspiration from the following quote from research biologist Albert Harris (Harris, 1994):​ “Systems of interacting forces and stimuli don’t have to be very complicated before the unaided human intuition can no longer predict accurately what the net result should be. At this point computer simulations, or other mathematical models, become necessary. Without the aid of mechanicians, and others skilled in simulation and modeling, developmental biology will remain a prisoner of our inadequate and conflicting physical intuitions and metaphors.” The theme of this chapter is summarized by a paragraph from the book entitled “How to Solve It” (Polya, 1945):​ “In order to translate a sentence from English into French two things are necessary. First, we must understand thoroughly the English sentence. Second, we must be familiar with the forms of expression peculiar to the French language. The situation is very similar when we attempt to express in mathematical symbols a condition proposed in words. First, we must understand thoroughly the condition. Second, we must be familiar with the forms of mathematical expression.”