If I want to visualize the step-by-step construction process of MRS during the unification using ERG, which resources should I be looking into? I have read some information about LKB and LUI on the wiki but I am still not very sure what should i be getting. It would be great if anybody here can suggest some materials for me to read and follow. I am using Mac OS X by the way. Thank you!
You should be able to use LUI in combination with LKB or ACE to extract MRS structures for any node in a derivation tree by right-clicking the node and selecting MRS. This will give you some degree of intuition into the composition process.
Unfortunately there is no way that I am aware of to automatically format the data in a way comparable to the semantic algebra notation used by Ann Copestake’s paper on that topic, which is what it sounds like you really want.
Technically, all of the information on how the composition happens is present in the feature structures corresponding to those tree nodes. You can wade through those structures to find the relevant data. I would recommend typically collapsing the CAT structures and looking at the CONT structures. Chasing reentrancies (right-clicking them can be helpful, again) can help you see where information is coming from. This is not a super fun project though.