diff --git a/C/utilpreds.c b/C/utilpreds.c
index 343fb109d..e7e4b8375 100644
--- a/C/utilpreds.c
+++ b/C/utilpreds.c
@@ -328,12 +328,12 @@ CopyTerm(Term inp, UInt arity) {
 	  goto restart_attached;
 	}
       }
-      return(Hi[0]);
+      return Hi[0];
     }
 #endif
-    return(MkVarTerm());
+    return MkVarTerm();
   } else if (IsPrimitiveTerm(t)) {
-    return(t);
+    return t;
   } else if (IsPairTerm(t)) {
     Term tf;
     CELL *ap;
@@ -366,7 +366,7 @@ CopyTerm(Term inp, UInt arity) {
 	}
       }
     }
-    return(tf);
+    return tf;
   } else {
     Functor f = FunctorOfTerm(t);
     Term tf;
@@ -403,7 +403,7 @@ CopyTerm(Term inp, UInt arity) {
 	}
       }
     }
-    return(tf);
+    return tf;
   }
 }
  
@@ -1940,7 +1940,7 @@ void Yap_InitUtilCPreds(void)
 {
   Term cm = CurrentModule;
   Yap_InitCPred("copy_term", 2, p_copy_term, 0);
-  Yap_InitCPred("copy_term_nat", 2, p_copy_term_no_delays, HiddenPredFlag);
+  Yap_InitCPred("copy_term_nat", 2, p_copy_term_no_delays, 0);
   Yap_InitCPred("ground", 1, p_ground, SafePredFlag);
   Yap_InitCPred("$variables_in_term", 3, p_variables_in_term, SafePredFlag|HiddenPredFlag);
   Yap_InitCPred("$non_singletons_in_term", 3, p_non_singletons_in_term, SafePredFlag|HiddenPredFlag);
diff --git a/Makefile.in b/Makefile.in
index d43f32d6d..2e02aa269 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -545,7 +545,7 @@ install_data:
 	(cd LGPL/clp ; make install)
 	(cd LGPL/clpr ; make install)
 #	(cd CHR ; make install)
-#	(cd LGPL/chr ; make install)
+	(cd LGPL/chr ; make install)
 	(cd CLPBN ; make install)
 
 
diff --git a/configure b/configure
index d4beef5b9..32cbc6409 100755
--- a/configure
+++ b/configure
@@ -847,9 +847,9 @@ Optional Features:
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
  --enable-tabling           support tabling
  --enable-or-parallelism    support or-parallelism as: env-copy,sba,a-cow
+ --enable-depth-limit       support depth-bound computation
  --enable-rational-trees    support infinite rational trees
  --enable-coroutining       support co-routining, attributed variables and constraints
- --enable-depth-limit       support depth-bound computation
  --enable-wam-profile       support low level profiling of abstract machine
  --enable-low-level-tracer  support support for procedure-call tracing
  --enable-threads           support system threads
@@ -2279,18 +2279,6 @@ else
 fi;
 if test "$tabling" = yes -o "$orparallelism" = yes -o "$threads" = yes
 then
-# Check whether --enable-rational-trees or --disable-rational-trees was given.
-if test "${enable_rational_trees+set}" = set; then
-  enableval="$enable_rational_trees"
-  rationaltrees="$enableval" ; rationaltrees=yes
-fi;
-# Check whether --enable-coroutining or --disable-coroutining was given.
-if test "${enable_coroutining+set}" = set; then
-  enableval="$enable_coroutining"
-  rationaltrees="$enableval";coroutining="$enableval"
-else
-  coroutining=no
-fi;
 # Check whether --enable-depth-limit or --disable-depth-limit was given.
 if test "${enable_depth_limit+set}" = set; then
   enableval="$enable_depth_limit"
@@ -2302,7 +2290,9 @@ else
 # Check whether --enable-rational-trees or --disable-rational-trees was given.
 if test "${enable_rational_trees+set}" = set; then
   enableval="$enable_rational_trees"
-  rationaltrees="$enableval" ; rationaltrees=no
+  rationaltrees="$enableval"
+else
+  rationaltrees=yes
 fi;
 # Check whether --enable-coroutining or --disable-coroutining was given.
 if test "${enable_coroutining+set}" = set; then
diff --git a/configure.in b/configure.in
index feec5fee2..39b4902ea 100644
--- a/configure.in
+++ b/configure.in
@@ -23,19 +23,13 @@ AC_ARG_ENABLE(or-parallelism,
 	orparallelism="$enableval", orparallelism=no)
 if test "$tabling" = yes -o "$orparallelism" = yes -o "$threads" = yes
 then
-AC_ARG_ENABLE(rational-trees,
-	[ --enable-rational-trees    support infinite rational trees ],
-	rationaltrees="$enableval" ; rationaltrees=yes)
-AC_ARG_ENABLE(coroutining,
-	[ --enable-coroutining       support co-routining, attributed variables and constraints],
-	rationaltrees="$enableval";coroutining="$enableval", coroutining=no)
 AC_ARG_ENABLE(depth-limit,
 	[ --enable-depth-limit       support depth-bound computation ],
 	depthlimit="$enableval", depthlimit=no)
 else
 AC_ARG_ENABLE(rational-trees,
 	[ --enable-rational-trees    support infinite rational trees ],
-	rationaltrees="$enableval" ; rationaltrees=no)
+	rationaltrees="$enableval" , rationaltrees=yes)
 AC_ARG_ENABLE(coroutining,
 	[ --enable-coroutining       support co-routining, attributed variables and constraints],
 	rationaltrees="$enableval";coroutining="$enableval", coroutining=yes)