Before revision:  The genotype space is taken to be a Cartesian power graph A ^L, where L is the number of genetic loci and the allele graph A encodes the possible allelic states and mutational transitions on one locus.
After revision:  The genotype space is taken to be a Cartesian power graph \mathcal{A ^L, where L is the number of genetic loci and the allele graph A encodes the possible allelic states and mutational transitions on one locus.