From: jim
Date: Mon, 6 Apr 2015 16:07:23 +0000 (-0400)
Subject: remarks on T
X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=0537916fdf69d4875a7998560fbc0b38177666e3
remarks on T
---
diff --git a/topics/week8_reader_monad.mdwn b/topics/week8_reader_monad.mdwn
index f201b29e..ff4310c3 100644
--- a/topics/week8_reader_monad.mdwn
+++ b/topics/week8_reader_monad.mdwn
@@ -449,7 +449,11 @@ arguments reversed (i.e., `(z k xx) == (xx >>= k)`).
(The `T` combinator in the derivations above is given by `T x <~~> \f. f x`;
it handles situations in which English word order reverses
-the usual function/argument order.)
+the usual function/argument order. `T` is what Curry and Steedman call this
+combinator. Jacobson calls it "lift", but it shouldn't be confused with the
+`mid` and `map` operations that lift values into the Reader monad we're focusing
+on here. It does lift values into a *different* monad, that we'll consider in
+a few weeks.)
In other words,
Jacobson's variable-free semantics is essentially a Reader monad.