Abstract:We investigate loops defined upon the product $\Bbb Z_m\times \Bbb Z_k$ by the formula $(a,i)(b,j) = ((a+b)/(1+tf^i(0)f^j(0)), i + j)$, where $f(x) = (sx + 1)/(tx+1)$, for appropriate parameters $s,t \in \Bbb Z_m^*$. Each such loop is coupled to a 2-cocycle (in the group-theoretical sense) and this connection makes it possible to prove that the loop possesses a metacyclic inner mapping group. If $s=1$, then the loop is an A-loop. Questions of isotopism and isomorphism are considered in detail.
Keywords: A-loop, nucleus, inner mapping group, cocycle, linear fractional
AMS Subject Classification: Primary 20N05; Secondary 08A052