has_variant_part genomic variation complement Note that even a reference feature (e.g. a wild-type gene) that is a member of a single locus complement that contains a variant allele is included in this 'genomic variation complement'. Thus, the members of this 'genomic variation complement' (which is a sequence collection) are 'single locus variant complements'. Our axiom below uses has_part rather than has_member, however, to account for the fact that many 'genomic variation complements' have only one 'single locus variant complement' as members. So because has_member is not reflexive, it is not appropriate for these cases. A genomic feature set representing all 'variant single locus complements' in a single genome, which together constitute the 'variant' component of a genomic genotype. A 'complement' refers to an exhaustive collection of *all* objects that make up some well-defined set. Such a complement may contain 0, 1, or more than one members. The notion of a complement is useful for defining many biologically-relevant sets of sequence features. Here, a 'genomic variation complement' is the set of all 'single locus complements' in a particular genome that harbor some known variation. In model organisms, the majority of genotypes describe variation at a single location in the genome (ie only one 'single-locus variant complement') that are variant realtive to some reference background. For example, the genotype instance 'fgf8a<t1282a/+>(AB)') exhibits a mutation at only one locus. But some genotypes describe variation at more than one location (e.g. a double mutant that has alterations in the fgf8a gene and the shh gene)). variant single locus complement genomic feature set