{"subshape": "pair of points", "shape": "arrow"}
{"subshape": "pair of points", "shape": "span"}
{"subshape": "pair of points", "shape": "cospan"}
{"subshape": "pair of points", "shape": "pair of parallel arrows"}
{"subshape": "pair of points", "shape": "tower"}
{"subshape": "pair of points", "shape": "endomorphism"}
{"subshape": "pair of points", "shape": "transfinite composition"}