From: Jim Pryor <profjim@jimpryor.net>
Date: Tue, 26 Oct 2010 14:18:02 +0000 (-0400)
Subject: ass5: omega->blackhole
X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=0d85c76d0d37b32bf99483b86828a7d2829db44e

ass5: omega->blackhole

Signed-off-by: Jim Pryor <profjim@jimpryor.net>
---

diff --git a/assignment5.mdwn b/assignment5.mdwn
index 61096c4e..02c0ac4d 100644
--- a/assignment5.mdwn
+++ b/assignment5.mdwn
@@ -35,38 +35,38 @@ Types and OCaml
 
 2.	Throughout this problem, assume that we have
 
-		let rec omega x = omega x;;
+		let rec blackhole x = blackhole x;;
 
 	All of the following are well-typed.
 	Which ones terminate?  What are the generalizations?
 
-		omega;;
+		blackhole;;
 
-		omega ();;
+		blackhole ();;
 
-		fun () -> omega ();;
+		fun () -> blackhole ();;
 
-		(fun () -> omega ()) ();;
+		(fun () -> blackhole ()) ();;
 
-		if true then omega else omega;;
+		if true then blackhole else blackhole;;
 
-		if false then omega else omega;;
+		if false then blackhole else blackhole;;
 
-		if true then omega else omega ();;
+		if true then blackhole else blackhole ();;
 
-		if false then omega else omega ();;
+		if false then blackhole else blackhole ();;
 
-		if true then omega () else omega;;
+		if true then blackhole () else blackhole;;
 
-		if false then omega () else omega;;
+		if false then blackhole () else blackhole;;
 
-		if true then omega () else omega ();;
+		if true then blackhole () else blackhole ();;
 
-		if false then omega () else omega ();;
+		if false then blackhole () else blackhole ();;
 
-		let _ = omega in 2;;
+		let _ = blackhole in 2;;
 
-		let _ = omega () in 2;;
+		let _ = blackhole () in 2;;
 
 3.	This problem is to begin thinking about controlling order of evaluation.
 The following expression is an attempt to make explicit the
@@ -104,15 +104,15 @@ and that "bool" is any boolean.  Then we can try the following:
 
 	However,
 
-		let rec omega x = omega x in
-		if true then omega else omega ();;
+		let rec blackhole x = blackhole x in
+		if true then blackhole else blackhole ();;
 
 	terminates, but
 
-		let rec omega x = omega x in
+		let rec blackhole x = blackhole x in
 		let b = true in
-		let y = omega in
-		let n = omega () in
+		let y = blackhole in
+		let n = blackhole () in
 		match b with true -> y | false -> n;;
 
 	does not terminate.  Incidentally, `match bool with true -> yes |