radix; Ramsey Frank Plumpton; Ramus Petrus - Pierre de la Ramee; Rand Ayn - Alissa Rosenbaum; random; randomness; range; rational; rationalism; rationalist; rational numbers; raw data; Rawls John; real; realisation; realism; realism perceptual; realist; reality; real number; real-time; Real World; reason; recipient; recollection; record; recourse; recursion; recursive; recursive definition; recursive function; recursive function theory; recursive set; recursive type; reductio ad absurdum; reduction; reductionism; redundancy; redundancy theory of truth; re-engineering; reference; reflection; reflexive; reflexive domain; Reflexive transitive closure; refutable; Regan Tom; Regis Pierre-Sylvain; regression; Reichenbach Hans; Reid Thomas; reification; reify; reinvent the wheel; relation; relational algebra; relational calculus; relative consistency proof; relatively prime; relativism; relevance; reliability; Reliability, Availability, Serviceability; reliable communication; renaissance; replacement - rules of; representation; representationalism; repression; requirements; requirements analysis; Requirements Engineering; res cogitans - res extensa; residues - method of; resolution; responsibility; restructuring; reusability; reuse; revealed theology; reverse engineering; Reverse Polish Notation; Ricoeur Paul; Riemann Georg Friedrich Bernhard; rights; rigid designator; ring network; ring topology; Ritchie David George; robot; robust; Rohault Jacques; romanticism; Rorty Richard; Ross William David; Rousseau Jean-Jacques; routine; Royce Josiah; Ruddick Sara Loop; rule; rules of inference; run-time; Russell Bertrand Arthur William; Russell's Attic; Russell's Paradox; Russell's theory of descriptions; Ryle Gilbert;