Relation R: R(a,a) R(b,b), R(b, c) R(c,c) R(0,x) x = 0, a, b, c, 1 R(x,1) x = 0, a, b, c, 1 Orthosupplement: 0 a b c 1 0 a c b 1 Candidates to fill: (0, a), (0, b), (0, c), (0, 1)*, (a, a)*, (b, b), (b, c)*