[PRL] Newton's Laws of Computation?

[Mitchell Wand]

Matthias asked me the following question a couple of weeks ago:

What are the equivalent of Newton's Laws for computation?

This morning I was surprised to discover that I already knew them.
Here they are:

First Law of Computation (Church's Law):

    ((\x.M) N) = M[N/x]

Second Law of Computation (von Neumann's Law)

     (s[l=v])(l') = {v      if l=l'
                      {s(l')  if l !=l'

Third Law of Computation (Hoare's Law)

     if P*B{S}P, then P{while B do S}P&~B

Variant Version of Hoare's Law (Peano's Law)

      if P(0) and (all k)(P(k) => P(k+1)), then (all k)P(k)

These laws all have the property that they are succinctly stated, they
embody an important principle for predicting the behavior of
computations, and in order to understand them, you have to import an
important body of knowledge about computation.

So my question for the morning is:  Can you state other laws of
computation that are equivalently fundamental and succinct?

--Mitch