What is predicate logic?

Predicate logic: • Constant –models a specific object. Examples: “John”, “France”, “7” • Variable – represents object of specific type (defined by the. universe of discourse) Examples: x, y (universe of discourse can be people, students, numbers) • Predicate – over one, two or many variables or constants.

What are monadic predicates?

Monadic Predicates:Express properties of objects. Monadic predicates apply to only one object at a time. Monadic predicates are represented by a capital letter followed by exactly one variable letter, e.g., ‘Fx’, Gx’, Hx’ , say, respectively, “x (a variable quantity) has property F”, “x has property G”, and “x has property H”.

What is the difference between individual variables and place predicates?

n-place predicates(A, B, C, D, E) are like predicate terms that refer to properties that belong to objects. For example, is blue, is happy, is taller than, etc. individual variablesare like placeholders for objects, e.g. in “x is happy” x is a placeholder for some name we could insert to make that statement true or false.

What are the limitations of propositional and categorical logic?

Despite the power of propositional and categorical logic, these forms of logic suffer from some severe limitations. Some arguments that are clearly valid cannot be shown valid in our system. Propositional logic misses the internal structure of sentences. Syllogistic logic cannot deal with more than 5 terms, nor can it deal with relations.

What are the types of quantified sentences in relational logic?

There are two types of quantified sentences in Relational Logic, viz. universally quantified sentences and existentially quantified sentences. A universally quantified sentenceis used to assert that all objects have a certain property.

Why are variables and constants only arguments of predicates?

1Predicate logic also allows arguments that are more complicated expressions than single variables or constants. These are important for certain purposes that we do not discuss in this book. Therefore, in this chapter we shall only see variables and constants as arguments of predicates.

What is the difference between propositional logic and relational logic?

In Propositional Logic, sentences are constructed from a basic vocabulary of propositional constants. In Relational Logic, there are no propositional constants; instead we have object constants, relation constants, and variables.