Araújo, JoãoKonieczny, Janusz2015-03-242015-03-242005Araújo, João; Konieczny, Janusz - Dense relations are determined by their endomorphism monoids. "Semigroup Forum" [Em linha]. ISSN 0037-1912 (Print) 1432-2137 (Online). Vol. 70, nº 2 (2005), p. 1-40037-19121432-2137http://hdl.handle.net/10400.2/3805We introduce the class of dense relations on a set X and prove that for any finitary or infinitary dense relation ρ on X , the relational system (X, ρ) is determined up to semi-isomorphism by the monoid End (X, ρ) of endomorphisms of (X, ρ). In the case of binary relations, a semi-isomorphism is an isomorphism or an anti-isomorphism.engjournal article10.1007/s00233-004-0164-7