The set of information elements can be canonically defined via dichotomy systems under which the kindred intertype relation is invariant when mapped to a vector space induced by the system. Although all 16 “Varlawend” dichotomy systems preserve the orbital 2-cocycle, orbital preservation alone is insufficient to guarantee kindred invariance. Among these systems, only two (D2 and D14) fix the kindred relation. In each of these systems, a heptad of dichotomies suffices to distinguish the information metabolism elements (IMEs) uniquely. For more information on which relationships are invariant when mapped to the vector space, check out the Appendices in A Representation-Theoretic Framework for Intertype Relations in Socionics.
Side Note: HEF = High Energy Function. These correspond to the Energetic functions of Model-G, which is a Gulenko-Newman trait. Alternatively, ‘HEF’ can be understood as a syntactic placeholder term for the subset that constitutes the identity, benefactor, supervisee and dual relations of the group that comprises all classical intertype relationships. For more information on the Gulenko-Newman dichotomies, check out Encyclopaedia of Model G and Model A Dichotomy Systems (contains proofs of new mathematical discoveries). And for information on how various function dichotomies translate to tetrachotomies for sociotype under the interpretation of injection, check out Injections - Function Dichotomies to TIM Tetrachotomies.