Lambda DCS Logical Forms

As I dove into the problem, I needed to learn the basic concepts surrounding it, and this involved learning a way of expressing knowledge base queries: Lambda DCS. I'm converting plain-text questions ("How often does the Washington Post come out?") to a "targetFormula," which is a lambda DCS logical form (DCS stands for dependency-based compositional semantics) and this looks like this:

(!fb:book.periodical_frequency.issues_per_year (!fb:book.periodical.frequency_or_issues_per_year fb:en.the_washington_post))

For some examples, this can get very confusing and isn't what it seems. It might look like simple function application but it is far from that, and I had been staring at these for too long before realizing this. This page explains them in full detail and makes them very easy to understand.

A single entity such as fb:en.the_washington_post is what it is: the Washington Post. More complicated are entities such as fb:book.periodical.frequency_or_issues_per_year store a set of key-value pairs, and in this case, stores each "periodical" along with its corresponding "frequency or issues per year," using the terminology provided. When they're put together inside the parentheses, the second part is matched against the right hand part of the first, and any matching tuples are returned. In this case, because there is a ! before the first part, each tuple it represents will be reversed. It's like saying "give me all the periodicals and their frequency and tell me the frequency of the one called 'the washington post'." Note that this is just the inner section of the logical form, but the outer section does essentially the same thing.

Lambda DCS is an interesting tool to use because it handles data in a novel way, at least to me. I'm excited to see how well Kparser-generated graphs can map onto them.