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On the use of pairwise balanced designs and closure spaces in the construction of structures of degree at least 3. (English) Zbl 0734.05020

Summary: We prove that a set of v-2 symmetric idempotent latin squares of order v, such that no two of them agree in an off-diagonal position, exists for all sufficiently large odd v. We describe how the techniques used in the proof relate to techniques used in [IMA Vol. Math. Appl. 20, 368-378 (1990; Zbl 0727.05010)] to construct generalized idempotent ternary quasigroups whose conjugate invariant group contains some specified subgroup. We also show how these techniques fit into the more general context of trying to extend group divisible design methods to combinatorial structures with \(t>3\), using closure spaces.

MSC:

05B05 Combinatorial aspects of block designs
05B15 Orthogonal arrays, Latin squares, Room squares
05B07 Triple systems
51E10 Steiner systems in finite geometry
20N05 Loops, quasigroups

Citations:

Zbl 0727.05010