Compared to Grammars/gra_nodangle.gap, each terminal base-pair of a stem is now considered to be dangled onto it in four different ways: not at all (drem
), only upstream neighboring base dangles (edl
), only downstream neighboring base dangles (edr
) or upstream and downstream neighboring bases dangle both (edlr
). The same holds for stems within multiloops: ml
, mldl
, mldr
, mldlr
. While this is conceptional clean, it inflates the search space and makes the grammar semantically ambiguous regarding the Vienna-Dot-Bracket notation.