create domainVector...
domainVector: [[a, b, c], [0,1,2]]
compute cartesian product...
[a, 0]
[b, 0]
[c, 0]
[a, 1]
[b, 1]
[c, 1]
[a, 2]
[b, 2]
[c, 2]
compute 1-boundary...
[a, 0]
[c, 0]
[a, 2]
[c, 2]
compute 2-boundary...
[b, 1]
generate length/index pairs...
[1, 0]
[2, 0]
[2, 1]
[3, 0]
[3, 2]
[4, 0]
[4, 3]
[5, 0]
[5, 4]