From 96acca9ada515033cfa9b50bb36c1ca0bffe15dc Mon Sep 17 00:00:00 2001
From: simonpj <unknown>
Date: Tue, 18 Jul 2000 14:47:52 +0000
Subject: [PATCH] [project @ 2000-07-18 14:47:52 by simonpj] Add comment

---
 ghc/compiler/simplCore/SetLevels.lhs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ghc/compiler/simplCore/SetLevels.lhs b/ghc/compiler/simplCore/SetLevels.lhs
index 5c83b6419b9f..51a46766bcb3 100644
--- a/ghc/compiler/simplCore/SetLevels.lhs
+++ b/ghc/compiler/simplCore/SetLevels.lhs
@@ -29,6 +29,11 @@
    This means that a sub-expression involving x is not "trapped" inside the RHS.
    And it's not inconvenient because we already have a substitution.
 
+  Note that this is EXACTLY BACKWARDS from the what the simplifier does.
+  The simplifier tries to get rid of occurrences of x, in favour of wild,
+  in the hope that there will only be one remaining occurrence of x, namely
+  the scrutinee of the case, and we can inline it.  
+
 \begin{code}
 module SetLevels (
 	setLevels,
-- 
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