One of the first things that you can do, once you have a moderately efficient calculus for boolean functions or propositional logic, is to start thinking about, and even to start computing, the differentials of these functions or propositions.
+
An efficient calculus for boolean functions and logical propositions makes it feasible to compute the finite differences and the differentials of those functions and propositions.
−
Let us start with a proposition of the form <math>p ~\operatorname{and}~ q</math> that is graphed as two labels attached to a root node:
+
For example, consider a proposition of the form <math>{}^{\backprime\backprime} p ~\operatorname{and}~ q \, {}^{\prime\prime}</math> that is graphed as two letters attached to a root node: