Injective vector valued semigroups.
We study invertibility of operations that are composition of two operations of arbitrary arities. We find the criterion for quasigroups and specifications for -quasigroups. For this purpose we introduce notions of perpendicularity of operations and hypercubes. They differ from the previously introduced notions of orthogonality of operations and hypercubes [Belyavskaya G., Mullen G.L.: Orthogonal hypercubes and -ary operations, Quasigroups Related Systems 13 (2005), no. 1, 73–86]. We establish...