A block , comprising: a base comprising a first block side , wherein the first block side comprises a first side plane defining a first base surface , the first base surface being a distally innermost surface on the first block side ; a middle connective protrusion coupled to the base and extending distally outwardly and at an angle between plus and minus 10 degrees from perpendicular from the base and the first side plane , wherein the middle connective protrusion is adjacent to the first base surface and comprises a middle center pillar coupled to the base extending distally outward from the base and the first side plane for a middle center pillar length , a middle base portion coupled to the middle center pillar and the base and extending axially and at an angle between plus and minus 10 degrees from perpendicular from the middle center pillar in a first direction for a middle base portion length , wherein the middle base portion comprises a middle base portion width being the distance the middle base portion extends distally outward from the base and the first side plane to the distally outermost surface of middle base portion , and a middle overhang portion coupled to the middle center pillar extending axially and at an angle between plus and minus 10 degrees from perpendicular from the middle center pillar in a second direction opposite the first direction for a middle overhang portion length such that there is a middle overhang space between the first side plane and the middle overhang portion , wherein the middle overhang portion comprises a middle overhang portion width being the distal distance of the middle overhang portion spanning from the middle overhang space to a middle protrusion top surface of the middle connective protrusion , wherein the middle overhang space comprises a middle overhang space width , which is the distal distance between the first side plane and the middle overhang portion . a base comprising a first block side , wherein the first block side comprises a first side plane defining a first base surface , the first base surface being a distally innermost surface on the first block side ; a middle connective protrusion coupled to the base and extending distally outwardly and at an angle between plus and minus 10 degrees from perpendicular from the base and the first side plane , wherein the middle connective protrusion is adjacent to the first base surface and comprises a middle center pillar coupled to the base extending distally outward from the base and the first side plane for a middle center pillar length , a middle base portion coupled to the middle center pillar and the base and extending axially and at an angle between plus and minus 10 degrees from perpendicular from the middle center pillar in a first direction for a middle base portion length , wherein the middle base portion comprises a middle base portion width being the distance the middle base portion extends distally outward from the base and the first side plane to the distally outermost surface of middle base portion , and a middle overhang portion coupled to the middle center pillar extending axially and at an angle between plus and minus 10 degrees from perpendicular from the middle center pillar in a second direction opposite the first direction for a middle overhang portion length such that there is a middle overhang space between the first side plane and the middle overhang portion , wherein the middle overhang portion comprises a middle overhang portion width being the distal distance of the middle overhang portion spanning from the middle overhang space to a middle protrusion top surface of the middle connective protrusion , wherein the middle overhang space comprises a middle overhang space width , which is the distal distance between the first side plane and the middle overhang portion . <EOS>