“…where D + = D + a× ȧ, the orientation character is trivial on I a× ȧ, and b ∈ D + \ I a× ȧ. The groups and maps involved in (3.7) are known from [19], [20], [17], [21], p. 527, and [22]. Since the notation in these works differs from the notation introduced above, we describe the relationship between the Wall and Browder-Livesay groups using two different systems of notation.…”