We establish a canonical correspondence between connected quandles and certain configurations in transitive groups, called quandle envelopes. This correspondence allows us to efficiently enumerate connected quandles of small orders, and present new proofs concerning connected quandles of order p and 2p. We also present a new characterization of connected quandles that are affine.2000 Mathematics Subject Classification. Primary: 57M27. Secondary: 20N02, 20B10. Key words and phrases. Quandle, connected quandle, homogeneous quandle, affine quandle, enumeration of quandles, quandle envelope, transitive group of degree 2p. results on connected quandles in a simpler and faster way. We focus on enumeration of "small" connected quandles, namely those of order less than 48 (see Section 8 and Algorithm 8.1) and those with p or 2p elements (see Section 9). Our proof of non-existence of connected quandles with 2p elements, for any prime p > 5, is based on a new group-theoretical result for transitive groups of degree 2p, Theorem 10.1.The modern theory of quandles originated with Joyce's paper [24] and the introduction of the knot quandle, a complete invariant of oriented knots. Subsequently, quandles have been used as the basis of various knot invariants [4,5,6] and in algorithms on knot recognition [6,14].But the roots of quandle theory are much older, going back to self-distributive quasigroups, or latin quandles in today's terminology, see [38] for a comprehensive survey of results on latin quandles and their relation to the modern theory. Another vein of results has been motivated by the abstract properties of reflections on differentiable manifolds [27,30], resulting in what is now called involutory quandles [39]. Yet another source of historical examples is furnished by conjugation in groups, which eventually led to the discovery of the above-mentioned knot quandle by Joyce and Matveev [24,31].

Abstract. A loop identity is of Bol-Moufang type if two of its three variables occur once on each side, the third variable occurs twice on each side, and the order in which the variables appear on both sides is the same, viz. ((xy)x)z = x(y(xz)). Loop varieties defined by one identity of Bol-Moufang type include groups, Bol loops, Moufang loops and C-loops. We show that there are exactly 14 such varieties, and determine all inclusions between them, providing all necessary counterexamples, too. This extends and completes the programme of Fenyves [5].

An autotopism of a Latin square is a triple (α, β, γ) of permutations such that the Latin square is mapped to itself by permuting its rows by α, columns by β, and symbols by γ. Let Atp(n) be the set of all autotopisms of Latin squares of order n. Whether a triple (α, β, γ) of permutations belongs to Atp(n) depends only on the cycle structures of α, β and γ. We establish a number of necessary conditions for (α, β, γ) to be in Atp(n), and use them to determine Atp(n) for n 17. For general n we determine if (α, α, α) ∈ Atp(n) (that is, if α is an automorphism of some quasigroup of order n), provided that either α has at most three cycles other than fixed points or that the non-fixed points of α are in cycles of the same length.

Abstract. An automorphic loop (or A-loop) is a loop whose inner mappings are automorphisms. Every element of a commutative A-loop generates a group, and (xy) −1 = x −1 y −1 holds. Let Q be a finite commutative A-loop and p a prime. The loop Q has order a power of p if and only if every element of Q has order a power of p. The loop Q decomposes as a direct product of a loop of odd order and a loop of order a power of 2. If Q is of odd order, it is solvable. If A is a subloop of Q, then |A| divides |Q|. If p divides |Q|, then Q contains an element of order p. If there is a finite simple nonassociative commutative A-loop, it is of exponent 2.

A loop whose inner mappings are automorphisms is an automorphic loop (or A-loop). We characterize commutative (A-)loops with middle nucleus of index 2 and solve the isomorphism problem. Using this characterization and certain central extensions based on trilinear forms, we construct several classes of commutative A-loops of order a power of 2. We initiate the classification of commutative A-loops of small orders and also of order p 3 , where p is a prime.