From cbf542073af9c239529a144e017d9d540fb1de75 Mon Sep 17 00:00:00 2001 From: jim Date: Wed, 18 Mar 2015 22:32:18 -0400 Subject: [PATCH] update --- topics/_week6_plexy.mdwn | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/topics/_week6_plexy.mdwn b/topics/_week6_plexy.mdwn index 79d081e3..864d84e8 100644 --- a/topics/_week6_plexy.mdwn +++ b/topics/_week6_plexy.mdwn @@ -20,10 +20,10 @@ of *the solar system*, an object representing the relational concept denoted by *center*, and so on. It doesn't matter precisely what that structure is, as long as it has distinct internal parts. -Kaplan names this complex object "Plexy". On Kaplan's assumptions, +Kaplan names this complex object "Plexy". Simplifying Kaplan's presentation, let's suppose the name *Plexy* is directly referential, and refers to the complex object that represents the meaning of *the center of mass of the solar -system*. +system*. Now consider: 2. Plexy is a point. @@ -64,18 +64,20 @@ the meaning of (2) can be `<{P}, point>`: radically different, as desired. In terms of the type systems we'll be developing over the next few weeks, the type of a DP will be a *sum type*: the disjoint union of the class of objects that a directly referential term can refer to, and -the class of objects that can serve as the complex structure -corresponding to a DP that is not directly referential. +the class of objects that can serve as complex meaning structures +corresponding to DPs as in (1) that are not directly referential. ## Motivating Maybe -Kaplan goes on to use this solution to attack a different problem, the +At the end of his footnote, Kaplan suggests using his proposal to help with a different problem, the problem of non-referring names. Russell supposed that if a name had no referent (e.g., *Santa*), a sentence containing that name would have no meaning, since there would be no object to insert into the structure representing the meaning of that sentence. But on Kaplan's scheme, there is no problem: *Santa is hungry* would denote `<{}, -hungry>`. +hungry>`. This can't be confused with a sentence saying that the empty set is +hungry, since (supposing we directly refer to the empty set), that would +denote `<{{}},hungry>`. This second idea has some obvious flaws. For instance, it predicts that sentences that differ only in the choice of a non-referring name @@ -87,12 +89,11 @@ Setting aside such objections, we will see over and over again the utility of the general strategy instantiated in Kaplan's strategy for representing the meaning of directly-referential expressions: - Kaplan's rule for directly-referential expressions: - a directly referential expression E contributes either - {} if there is no object that E refers to, or else - {P} if E refers to P +> Kaplan's rule for directly-referential expressions: a directly referential expression E contributes either: +> {} if there is no object that E refers to, or else +> {P} if E refers to P -In later weeks, we will call the general form of this technique the Maybe type, and the general strategy for deploying this type the Maybe monad. +In later weeks, we will call the general form of this technique the "option" or "Maybe" type, and the general strategy for deploying this type "the Maybe monad." (In OCaml one has types like `int option`; in Haskell they are `Maybe Int`.) Kaplan, D. 1989. "Demonstratives. In J. Almog, J. Perry, & H. Wettstein -- 2.11.0