diallel

adj

1. (not-comparable)Involving crosses between several or all possible combinations.

   “Nine varieties were chosen for a diallel crossing”

   “The main difference with design II is that the same individuals are used as parents for the diallel mating design (individuals are used both as male and female).”

   “A series of diallel analyses (cf. Mather and Jinks, 1982) were performed to test for heterogeneity among lines of a given type.”

   “The diallel mating design is particularly well suited to characterizing genetic effects of inbred lines and their hybrid combinations .”

2. (not-comparable, rare)Of lines: Meeting and intersecting; not parallel.

   “[…] like conditions and common ends as the ideal and goal of human effort are attained along parallel and not diallel lines in all the diversities of human application and invention.”

   “Fundamental to this new theory is the discovery of diallel, gravitational-field lines. These connect the two bodies — providing a path for the gravitational information to flow. To see the evidence of these diallel lines in nature requires a paradigm shift away from the traditional view of gravitational interaction.”

   “[…] connecting diallel lines which provide not only particle flow between the bodies, but also the flow of photon and gravitational information as well […]”

noun

1. A set of all possible pairs of items from a specified set of items, especially when used for a study of diallel crosses.

   “Pollinations in 1956 and 1957 produced seed for eight replications of all 78 combinations of a complete half diallel, excluding selfs.”

   “However, complex gene action involving nonallelic interaction was found in the original 6×6 diallel.”

   “In a diallel, a set of genotypes are crossed in all possible combinations.”

2. A form of logical fallacy in which a proposition that is required to prove another proposition can only be proved by means of assuming the truth of the proposition one is trying to prove; circular reasoning.

   “Fifth is the diallel (ó διάλληλος τρóπος)—petitio principii—the fallacy of circle, or the method of showing that a proof which is employed to establish the truth of a proposition, can itself only be proved by the proposition in question: as for example, "if anyone should infer the authenticity of a certain history, from its recording such and such facts, the reality of which rests on the evidence of that history."”

   “In particular, Huet is said to apply the five tropoi of Agrippa (viz. relativity, diaphonia or disagreement, hypothesis or begging the question, infinite regress, and diallel or circular argument) to the cogito, the criterion of clarity and distinctness, and the proofs of the existence of God.”

   “This reminds us of what Sextus calls a diallel. A diallel is a situation where we need a in order to “prove” b and b in order to “prove” a (PH, I, 169), so that we can’t prove anything.”