High Quality Content by WIKIPEDIA articles! In mathematics and abstract algebra, a relation algebra is a residuated Boolean algebra equipped with an involution called "converse". The motivating example of a relation algebra is the algebra 2X² of all binary relations on a set X, with R S interpreted as the usual composition of binary relations and the converse of R as the inverse relation. Relation algebra emerged in the 19th century work of Augustus De Morgan and Charles Peirce, which culminated in the algebraic logic of Ernst Schröder. The present-day purely equational form or relation algebra was developed by Alfred Tarski and his students, starting in the 1940s.