<div dir="ltr"><div>I think there might be a quicker solution in this case (without replacing all diff-lists with "emerson-lists").</div><div><br></div><div>1-plus-list misleadingly named, because it actually insists on at least two elements in the list (1 plus something nonempty). If you use "QUE.LIST cons", that will insist on at least one element -- as long as the end of the list is closed. It looks like you're already closing the list (by using "LIST 0-1-list" or "LIST 1-list"). Closing a diff-list is dangerous because you'll never be able to append to it later, but as long as you're doing that at the top of the tree where you're not expecting any more QUE elements, that should be okay.</div><div><br></div><div>So at the top of the tree, you could have "QUE [ LIST cons, LAST null ]". Then you know you have at least one thing on the list (but will not be able to add anything more).<br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">2018-06-20 10:28 GMT+02:00 Francis Bond <span dir="ltr"><<a href="mailto:bond@ieee.org" target="_blank">bond@ieee.org</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">It appears the emerson-lists (see Berthold's talk at this summit and one of Guy's talk at the last one) would allow us to do this.</div><div class="gmail_extra"><div><div class="h5"><br><div class="gmail_quote">On Thu, Dec 1, 2016 at 2:51 AM, Zhen Zhen Fan <span dir="ltr"><<a href="mailto:zhenzhen.fan@gmail.com" target="_blank">zhenzhen.fan@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Dear developers,<br><div><br></div><div>We'd like to seek your help for this problem of dealing with diff-lists.<br></div><div><br>Chinese interrogatives have in-situ wh-questions, which have wh-words appearing at positions of arguments, specifiers, and modifiers. While implementing the analysis for these interrogatives, we <br><br>1. Define all wh-words to have its QUE containing an index (<! #index !>), and all other words to have QUE as 0-dlist. <br><br>2. Redefine SYNSEM.NON-LOCAL.QUE to be a diff-list instead of 0-1-dlist (to allow more than one wh-word to appear in a question), and make binary rules to append QUE values of their daughters, as shown below:<br><br>basic-binary-phrase :+<br> [ SYNSEM.NON-LOCAL.QUE [ LIST #first,<br> LAST #last ],<br> ARGS < sign & [ SYNSEM.NON-LOCAL.QUE [ LIST #first,<br> LAST #middle ] ],<br> sign & [ SYNSEM.NON-LOCAL.QUE [ LIST #middle,<br> LAST #last ] ] > ]. <br><br>3. Define the rule to identify clauses with at least one wh-word and set SF to "ques". The problem is how to define the constraint for a diff-list with at least one item inside. <br>We tried to use "QUE.LIST 1-plus-list", which works great to exclude sentences with 0 wh-word, and to parse sentences with 2 or more wh-words. For sentences with exactly 1 wh-word, some can be parsed and some can not. It turns out that it works correctly if the wh-word is the first ARG in the binary rule, and it won't parse if the wh-word is the second ARG in the binary rule.<br>So it seems that appending gives us different results for the two scenarios:<br>a) when wh-word is the 1st ARG, mother's QUE can unify with the constraint.<br>-- 1st ARG's QUE: diff-list <br> [ LIST < 6 > + 16LIST,<br> LAST 16 ]<br>-- 2nd ARG's QUE: diff-list <br> [ LIST 19 0-1-list,<br> LAST 19 ]<br>-- mother's QUE: diff-list<br> [ LIST <4> + 18 0-1-list,<br> LAST 18 ]<br>b) when wh-word is the 2nd ARG, mother's QUE can't unify with the constraint, complaining the conflict between 1-list and 1-plus-list.<br>-- 1st ARG's QUE: diff-list <br> [ LIST 28 0-1-list,<br> LAST 28 ]<br>-- 2nd ARG's QUE: diff-list <br> [ LIST < 6 > + 16LIST,<br> LAST 16 ]<br>-- mother's QUE: diff-list<br> [ LIST 1-list <4> + 11,<br> LAST 11 ]<br><br>How can this be resolved so that we get consistent results regardless of the position of wh-word in a binary rule?<br><br></div><div>We also notice that two daughters with QUE as 0-dlist lead to the mother's QUE as diff-list (not 0-dlist) with identical LIST and LAST.<br></div><div><br>We have also tried defining 1-list to inherit from 1-plus-list too. Then the above problems will disappear, but it will fail to exclude sentences containing no wh-word.<br><br></div><div>Many thanks!<br></div><div>Zhenzhen<br></div></div> </blockquote></div><br><br clear="all"><div><br></div></div></div><span class="HOEnZb"><font color="#888888">-- <br><div class="m_-684357322871782280gmail_signature" data-smartmail="gmail_signature">Francis Bond <<a href="http://www3.ntu.edu.sg/home/fcbond/" target="_blank">http://www3.ntu.edu.sg/home/<wbr>fcbond/</a>><br>Division of Linguistics and Multilingual Studies<br>Nanyang Technological University<br></div> </font></span></div> </blockquote></div><br></div>