RECONSTRUCTION OF BINARY RELATIONS FROM THEIR RESTRICTIONS OF CARDINALITY 2, 3, 4 and (<i>n</i> ‐ 1) II

Abstract

Abstract We shall prove here that any binary relation on a base E with cardinality n &gt; 6 is reconstructible from its restrictions of cardinality 2, 3, 4 and ( n ‐ 1). This proof needs results of part I of this paper where we characterize any pair of relations R , R ' which are 2‐, 3‐ and 4‐hypomorphic. As a corollary we obtain that any binary relation is ( n ‐ 4)‐reconstructible (when n &gt; 9).