unarypredikater

A unary predicate is a fundamental concept in formal logic and computer science, specifically within the realm of predicate logic. Unlike binary predicates, which relate two entities (e.g., "x is equal to y"), a unary predicate applies to a single entity, describing a property or attribute that the entity either possesses or does not possess. For example, the predicate "isPrime(n)" evaluates to true if the input *n* is a prime number and false otherwise. This type of predicate is often used to define conditions or constraints in logical expressions.

In predicate logic, unary predicates are expressed as functions that return a boolean value (true or false) based on the input. They are essential for constructing logical statements, such as quantifiers (e.g., "for all x, P(x) holds" or "there exists an x such that P(x) holds"). For instance, the statement "∀x (Even(x) → DivisibleByTwo(x))" asserts that for every *x*, if *x* is even, then it is divisible by two. Here, *Even(x)* is a unary predicate.

Unary predicates are widely used in programming, particularly in functional programming languages like Haskell or Prolog, where they serve as building blocks for more complex logical operations. They are also foundational in mathematical proofs, database queries (e.g., filtering records based on a condition), and automated reasoning systems. Their simplicity allows them to model a broad range of properties, making them versatile tools in both theoretical and applied contexts.