Chapter 3 - propositional calculus , predicate calculus

advantages of predicate calculus

- well defined formal semantics - sound - complete inference rules

first-order predicate calculus

Allows quantified variables to refer to objects in the domain of discourse and not to predicates or functions.

what is the important feature of predicate calculus?

The ability to infer new correct expressions from a set of true assertions

what do inference rules provide?

a computationally feasible way to determine an expression logically follows form another

What is predicate calculus used for?

a representational language for artificial intelligence

what is an atomic sentence?

calculus is a predicate of arity n followed by n terms enclosed in parentheses and separated by commas. (number of arguments)

what is the process of replacing the function with its value called?

evaluation

unification

is an algorithm for determining the substitutions needed to make two predicate calculus expressions match.

what does predicate calculus provide?

the ability to access individual assertations

what is propositional calculus?

they are denoted propositions or statements about the world that may either be true or false

what are they denoted by?

uppercase letters near the end of the english alphabet P,Q,R..

what can we do through inference rules

we can manipulate predicate calculus expressions accessing their individual components and inferring new sentences

what is propositional calculus used for?

we can represent and reason about properties and relationships in the world.