tuned text

--- a/src/HOL/SMT.thy	Fri Jan 07 15:59:10 2011 +0100
+++ b/src/HOL/SMT.thy	Fri Jan 07 17:58:51 2011 +0100
@@ -181,7 +181,8 @@
 
 Due to licensing restrictions, Yices and Z3 are not installed/enabled
 by default.  Z3 is free for non-commercial applications and can be enabled
-by simply setting the environment variable Z3_NON_COMMERCIAL to @{text yes}.
+by simply setting the environment variable @{text Z3_NON_COMMERCIAL} to
+@{text yes}.
 *}
 
 declare [[ smt_solver = cvc3 ]]