..E

effective
effective procedure
An effective procedure is an unambiguous prescription for computing some function or solving a class of problems.
effectively computable
A function is effectively computable if there is an effective procedure for computing the value of the function.
effectively decidable
A class of problems, or a set, is effectively decidable if there exists an effective procedure which will determine the answer to the problem (or membership of the set) terminating with the correct answer within a finite number of steps, for all candidates.
effectively semi-decidable
A class of problems, or a set, is effectively semi-decidable if there exists an effective procedure which terminates with a positive answer whenever the answer to the problem or the membership question is positive, but which may fail to terminate in the case that the answer is negative.
empirical
based on observation or experiment
empiricist
one who emphasises the role of sensory experience or experimental evidence in the justification of knowledge.
epistemology
The theory of knowledge.
epistemic logic
A logic for reasoning about knowledge and belief.
extension
of a set
the membership of the set
of a property
the collection of things which have the property
of a function
the mapping defined by the function, as distinct from any algorithm, rule or formula used to define the function
extensional
of a set theory
A set theory is extensional when two sets are equal iff they have the same extension.
of a higher-order logic
A higher order logic is extensional when two properties or functions are equal iff they have the same extension.