X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=hints%2Fassignment_7_hint_3.mdwn;h=bbdea69404d0b7f79861a29f718082692a35da81;hp=7617922b0a5c6faff407412b75f69ab7274874b7;hb=824a638b7070e9ae64a5124c4467a03fd0f18b00;hpb=458cadab1427b0fc0f7bc8689f1dddb18b2201e7 diff --git a/hints/assignment_7_hint_3.mdwn b/hints/assignment_7_hint_3.mdwn index 7617922b..bbdea694 100644 --- a/hints/assignment_7_hint_3.mdwn +++ b/hints/assignment_7_hint_3.mdwn @@ -17,7 +17,7 @@ * In def 2.5, GS&V say the denotation of an e-type constant α wrt a discourse possibility `(r, h, w)` is whatever entity the world `w` associates with α. Since we don't have worlds, this will just be an entity. - They say the denotation of a predicate is whatever extension the world `w` associates with the predicate. Since we don't have worlds, this will just be an extension. + They say the denotation of a predicate is whatever extension the world `w` associates with the predicate. Since we don't have worlds, this will just be an extension, or a function from entities to `bool`s. They say the denotation of a variable is the entity which the store `h` assigns to the index that the assignment function `r` assigns to the variable. In other words, if the variable is `'x'`, its denotation wrt `(r, h, w)` is `h[r['x']]`. In our OCaml implementation, that will be `List.nth h (r 'x')`. @@ -27,8 +27,6 @@ we'll just talk about \[[expression]] and let that be a monadic value, implemented in part by a function that takes `(r, h)` as an argument. - More specifically, \[[expression]] will be a set of `'a dpm`s, where `'a` is the appropriate type for *expression*. Each `'a dpm` is implemented by a function that takes `(r, h)` as an argument. - * In def 2.7, GS&V talk about an operation that takes an existing set of discourse possibilities, and *extends* each member in the set by (i) allocating a new location in the store, (ii) putting some entity `d` from the domain in that location, and (iii) assigning variable `x` to that location in the store. It will be useful to have a shorthand way of referring to this operation: