remarks on T

[lambda.git] / topics / week8_reader_monad.mdwn

diff --git a/topics/week8_reader_monad.mdwn b/topics/week8_reader_monad.mdwn
index f201b29..ff4310c 100644 (file)
--- 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 `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.
 
 In other words, 
 Jacobson's variable-free semantics is essentially a Reader monad.