Dan answered this question in the other thread, which I will paste here:
On your second topic, constraining passive participles, I think we can do a little better, though the solution is only partly theoretically sound. Since the passive lexical rule has an information-structure effect, there is an ICONS “topic” constraint linking the index of the passivized object with the event of the verb, so when you add this constraint to the input MRS for the generator, you’ll only see passive relative clauses, not the infinitival ones. So in your MRS for “the locked car …” you can add this line after the HCONS constraints;
ICONS: < e3 topic x1 >
where “e3” is the ARG0 of the “lock” EP and “x1” is the ARG2 of that EP. With this added constraint, you won’t generate “the car to lock”.
In order to also block generation of “the car locked”, we have to resort to a less satisfying solution which takes advantage of a slight difference in the MRSs of “locked car” and “car locked”, namely that the grammar constrains the aspect of the ARG0 of “locked” when it’s pre-nominal to be [PERF -] (non-perfect), but for no deep reason fails to assert this of “locked” when it’s a post-nominal modifier. So if you add [PERF -] to that ARG0 in your MRS input to the generator, you won’t get the output “car locked” because the generator has to produce an output which accounts for every element of the input MRS, and the generated structure for “car locked” won’t say anything about the value of PERF for the ARG0 of “lock”. That is, in your example MRS, the EP for lock_v_cause should read
[ _lock_v_cause LBL: h19 ARG0: e3 [e PERF: -] ARG1: i4 ARG2: x1 ]
With these two additions to the MRS you started with, you should see the behavior you want. for passive participles. Note that while “the car locked” doesn’t sound great, this post-modifier structure is not infrequent, as you see in examples such as “the papers rejected were still of good quality” and “the topics discussed cover a wide range of concerns”. I don’t yet have an account of how the unhappy “car locked” is different from the fine “topics discussed”, so the grammar doesn’t distinguish them.