Figure 1.

Loops with cuts have to be scored differently. Top row: hairpins and interior loops containing the cut between n₁ (black ball) and n₁ + 1 (white ball). Below: multi loops containing the cut. Neither M1 nor M components must start at n₁ + 1 or stop at n₁. Note that the construction of Z^M out of Z^M and Z^M1 ensures that the cut is not inside the loop part of Z^M either.