Sandbox

col 1 col 2 col 3&4
row a :2 a1-b1 :3_ a2-c3 a4
row b&c :2- b4
c1 c4
row d d1 d2 d3 d4
col 1 col 2 col 3 col 4
row 1 1 2 3
row 2 col span end
row 3 1 2 3