I’m trying to understand variables in the ERG and I apologize in advance for the long post. Let me start by stating what I think I know so far to make sure it is right:
Instances and Eventualities
In my mind I’ve divided the world of “terms” produced by an MRS EP in the ERG into two groups: quantifiers and predicates. “Quantifiers” have an (ARG0, RSTR, BODY) signature. Everything else I’m calling a “predicate” and will at least have an ARG0 but possibly other arguments.
I think I have my head around two types of variables:
- Instance variables (x) are always declared and bound by exactly one quantifier and can only be used by other terms in its scope
- They appear to always be referring to what I’ll call the “real world” (as opposed to the structure of the sentence, see next type…).
- After declaration, exactly one predicate can use this quantifier as its ARG0, but many other predicates can use it in other positions.
- Eventuality variables (e) appear to be declared and bound implicitly so they are visible to all terms, but are “introduced” or “owned” by exactly one predicate that has it in its ARG0 position. They appear to be used in at least two ways:
- To declare an “event” that is introduced by a verb and is something that conceptually (if you twist your mind a bit) exists in the world
- And also in a “meta” way, meaning that their purpose is modify the meaning of the words themselves (as opposed to modifying a “real world” thing) by allowing different terms to form relationships: like when you need to say “very” is modifying “slimy”
Every predicate has to uniquely “introduce” some kind of variable in ARG0, even if it isn’t used.
"a very slimy cave" _a_q(x4, and(_very_x_deg(e9, e10), _slimy_a_1(e10, x4), _cave_n_1(x4)), unknown(e2, x4))
- “_a_q(x4,…,…)” declares we are going to be talking about something in the world, eventually contained in “x4”, by declaring and binding that variable and then using the second argument to filter it down to what we are talking about.
- _cave_n_1(x4): tells us that we should filter x4 to be something that is a cave.
- _slimy_a_1(e10, x4): tells us to make sure the things in x4 are also slimy. And: since slimy can (potentially) be modified by (for example) degree of slimyness, it introduces an eventuality e10 for other terms to (optionally) attach to.
- _very_x_deg(e9, e10): Indeed does attach to slimy via e10, and introduces yet another eventuality because it might be modified too. Turns out it isn’t in this example.
Question 1: Am I on the right track so far?
Other Variable Types
As listed in erg.smi, there are a few other variable types in a hierarchy:
u. i < u. p < u. h < p. e < i : SF sf, TENSE tense, MOOD mood, PROG bool, PERF bool. x < i & p : PERS person, NUM number, GEND gender, IND bool, PT pt.
I found a one word description of the types of variables here: http://moin.delph-in.net/RmrsVpm?highlight=(variables)
event <> e ref-ind <> x individual <> i handle <> h non_event <> p * >> u semarg << u
Question 2: Is there a good conceptual description of those types somewhere?