RECONSTRUCTION OF BINARY RELATIONS FROM THEIR RESTRICTIONS OF CARDINALITY 2, 3, 4 and (n ‐ 1) II
Gérard Lopez, Claire Rauzy · Mathematical logic quarterly · 1992
Abstract We shall prove here that any binary relation on a base E with cardinality n > 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 > 9).