Definition:Propositional Function/Examples

Examples
Let the universe be the set of integers $\Z$.

Let $\map P x$ be the propositional function defined as:
 * $x$ is even

Then we can insert particular values of $x \in \Z$, for example, as follows:

Thus $\map P x$ is a unary propositional function (pronounced yoo-nary).

Let $\map P {x, y}$ be the propositional function defined as:
 * $x$ is less than $y$

Then we can create the propositional statements:

Thus $\map P {x, y}$ is a binary propositional function.

Let $\map P {x, y, z}$ be the propositional function defined as:
 * $x$ is between $y$ and $z$.

Then:

Thus $\map P {x, y, z}$ is a ternary propositional function.