A way to get the MRS Index for subtrees (like the target of "can ...")?

For all the examples of commands that I’ve tried, the Index of the MRS helpfully points to the E variable that indicates which verb that the command actually wants done.

For example, the phrase “get the diamond that shines” has two verbs, but the MRS Index points to get not to shine. This allows me to use different predicates for actually changing state vs. querying state. E.g. I’d query for diamonds that shine, but try to to change the state of the world by getting.

I’m struggling with words like “can”, as in “can you get the diamond that shines”. In this case, the MRS Index is can. In order to figure out if the system “can” do something, I need to speculatively execute it, and thus I need to attempt to “get the diamond that shines” and say “Yes!” if I can.

But, in order to do that, I need to know which of the verbs (get or shine) is the “Index” for that part of the sentence.

Is there a way to get that information from the ERG?

It should be the ARG1 of can.

Wow, that was too easy. I was so busy looking for things outside of the RELS structure that might help that I didn’t think of that. Thanks!