Specifically I am not seeing an edge for extracted complement rule in the chart, above the head-subject node highlighted in red (the one that’s there, highlighted in blue, is the adjunct extraction rule).
Can’t figure out why so far. Double checked the chart; there is only one daughter in the rule I am looking at (complement extraction). The rule ex-comp is in rules.tdl. I am not redisplaying the parse. It doesn’t seem to have to do with lexical entries or lexical rules?.. Help!!!
" Edges you are trying to use as daughters appear to be contiguous in the chart, but actually are not. This can happen because if the LKB can’t construct an edge for a lexical entry, it won’t put anything for that entry in the chart. It will, however, record the fact that there is something there, and not let constituents bridge the material it can’t account for. On the possible causes of this situation, see this FAQ."
I don’t understand what it is saying and the link to the FAQ is broken… It sounds like it would have to do with a terminal node though? Which definitely isn’t the case here.
Update: I don’t know why the edge was not in the chart (or conversely: why I was getting a unification result for it interactively), but for now, I was able to fix this using the solution mentioned here: Emerson (append) lists for subject extraction
Specifically, in the current version of matrix.tdl, we have the apparently unnecessary constraints in extracted-subject as well as extracted-complement rules. We should be able just to say that head-daughter’s SUBJ (or COMPS) contains a gap, and there is no need to say anything about head-daughter’s NONLOCAL.SLASH value.
So I made this change and now I do get a parse for a sentence with an extracted complement. Interestingly, I still haven’t removed the similar constraint from the subject extraction rule in this particular grammar, and subject extraction appears to work fine.