Propositional logic

Logical implication

An implication, also known as the material conditional, forms the conditional statement pqp \rightarrow q, read as “if pp then qq”. The behavior of this logical operator is often initially unintuitive (it was for me and most of my peers in early discrete mathematics): the statement pqp \rightarrow q is false only when pp is true and qq is false.

When pp is false, the first inclination one might have is to conclude the whole statement pqp \rightarrow q is false. However pp is the conditional component of the implication, and we must get through it first before asking about the truth value of qq. That is, if pp is true and qq ends up being false, then our whole implication breaks since it directly contradicts what the statement is claiming. However, if pp is false, then the implication is “not invoked”, or the conditional is not met; we don’t care about the truth value of pp for its own sake. This is the nature of vacuous truth, which seems to itself refer back to the pure definition of the material conditional; there seems to be a recursive trail when trying to find a way to the origin of the assigned truth under a false antecedent.