..R

range
the area over which a thing is distributed
- of a relation (in set theory) -
the set of elements or values which are related to some other element under the relation
rational
based on reason
rational number
a number which is either zero or the ratio of two non-zero whole numbers
hyper-rational

rationalist
one who emphasises the role of reason in the justification of knowledge.
real
not imaginary
real number
the limit of a convergent sequence of rationals
realism
belief in objective existence, often relative to some type of entity
recursive
involving self-reference
(in computer science and logic)
a definition of a function or procedure is recursive if it involves reference to the function or procedure being defined, i.e. if during evaluation the function or procedure may invoke itself (usually with different arguments).
recursive function (logic)
a recursive function is one which is effectively computable, whose evaluation always terminates with a result.
recursive set (logic)
a set is recursive if the question of membership in the set is effectively decidable.
recursively enumerable (logic)
a set is recursively enumerable if there is an effective procedure for enumerating the members of the set. Equivalently, if its membership question is semi-decidable.
regular
conforming to a standard, complete, thorough, absolute
regular ordinal
an ordinal is regular if it is a limit ordinal whose cofinality, cf(), is .
rhetoric
the art of effective or persuasive speaking or writing
relation
what one person or thing has to do with another
(logic, set theory)
a correspondence between two sets (say A, B) represented by a set of ordered pairs, each containing one element from A and one from B.
reify
convert into a thing, materialise
(computing, formal methods)
to realise an abstract specification as an executable program
hypostasis

representative
consisting of elected deputies
representative democracy
a democracy in which government effected by elected representatives of the people