X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?a=blobdiff_plain;f=week1.mdwn;h=ad6f98c43275194d2475d8810ecf0a1ddd9364d1;hb=e1fee6dac71060c16f35649488605d744f191c18;hp=67d5828df04449f17912577399937b77bf9dbe63;hpb=9357992afd5f243d6154d0d21d4fc2637ce1a925;p=lambda.git
diff --git a/week1.mdwn b/week1.mdwn
index 67d5828d..ad6f98c4 100644
--- a/week1.mdwn
+++ b/week1.mdwn
@@ -185,7 +185,7 @@ Different authors use different notations. Some authors use the term "contractio
M ~~> N
-We'll mean that you can get from M to N by one or more reduction steps. Hankin uses the symbol →
for one-step contraction, and the symbol &8608;
for zero-or-more step reduction. Hindley and Seldin use ⊳1
and ⊳
.
+We'll mean that you can get from M to N by one or more reduction steps. Hankin uses the symbol →
for one-step contraction, and the symbol ↠
for zero-or-more step reduction. Hindley and Seldin use ⊳1
and ⊳
.
When M and N are such that there's some P that M reduces to by zero or more steps, and that N also reduces to by zero or more steps, then we say that M and N are **beta-convertible**. We'll write that like this: