“…(5) 5) and the relation (13), one can deduce that Suppose that there exists (i 1 , i 3 , i 4 , i 5 , i 6 ) ∈ J such that b (i 1 ,i 3 ,i 4 ,i 5 ,i 6 ) = 0. Let (w 1 , w 3 , w 4 , w 5 , w 6 ) ∈ J be the greatest element (in the lexicographic order on N 3 × Z 2 ) of J such that b (w 1 ,w 3 ,w 4 ,w 5 ,w 6 ) = 0.…”