Basic hexagonal illustration approach. Here a line between two parent symbols (rhombus = either sex) represent marriage line as 1—1 means 1 x 1 and where genotype of both parents is different, two different writable crosses are possible as represented by arrows 0→1 = 0 x 1 and 1→0 = 1 x 0 etc. A, line-dot hexagon (Ld-hex) representing the line-dot offspring outcomes of nine possible writable parent genotype combinations. Here, dot = 0, one line passing through a dot = 1, two lines passing through a dot = 2; B, basic genotype hexagon (bG-hex) representing the ternary coded square offspring outcomes of nine possible writable parent genotype combinations.