X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=topics%2F_week5_system_F.mdwn;fp=topics%2F_week5_system_F.mdwn;h=e69eeb4d2447b9b4dcc89f1291519c345fbb8799;hp=ae0b7e056f75c12f353d55a2a6b9ceca22759dea;hb=de7e75d334623860b686900be73418598e5dccb7;hpb=b895ad012c22442151800347864a4b3f84f6de84
diff --git a/topics/_week5_system_F.mdwn b/topics/_week5_system_F.mdwn
index ae0b7e05..e69eeb4d 100644
--- a/topics/_week5_system_F.mdwn
+++ b/topics/_week5_system_F.mdwn
@@ -34,8 +34,7 @@ notational convention (which will last throughout the rest of the
course) that "x:α
" represents an expression `x`
whose type is α
.
-Then System F can be specified as follows (choosing notation that will
-match up with usage in O'Caml, whose type system is based on System F):
+Then System F can be specified as follows:
System F:
---------
@@ -47,7 +46,7 @@ constants play the role in System F that base types play in the
simply-typed lambda calculus. So in a lingusitics context, type
constants might include `e` and `t`. "α" is a type variable. The
tick mark just indicates that the variable ranges over types rather
-than over values; in various discussion below and later, type variable
+than over values; in various discussion below and later, type variables
can be distinguished by using letters from the greek alphabet
(α, β, etc.), or by using capital roman letters (X, Y,
etc.). "`Ï1 -> Ï2`" is the type of a function from expressions of
@@ -57,7 +56,7 @@ universal type, since it universally quantifies over the type variable
have at least one free occurrence of `α` somewhere inside of it.
In the definition of the expressions, we have variables "`x`" as usual.
-Abstracts "`λx:Ï. e`" are similar to abstracts in the simply-typed lambda
+Abstracts "`λx:Ï.e`" are similar to abstracts in the simply-typed lambda
calculus, except that they have their shrug variable annotated with a
type. Applications "`e1 e2`" are just like in the simply-typed lambda calculus.