diff --git a/configure b/configure
index 018950ad1..55e3e52f1 100755
--- a/configure
+++ b/configure
@@ -1481,7 +1481,7 @@ Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
   --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
  --with-gmp=DIR           use GNU Multiple Precision in DIR
- --with-yapr=DIR           use GNU Multiple Precision in DIR
+ --with-yapr=DIR           interface to R language, R installed in DIR
  --enable-minisat           use minisat interface
  --with-cudd=DIR           use CUDD package in DIR
  --with-java=JAVA_HOME       use Java instalation in JAVA_HOME
@@ -4432,7 +4432,6 @@ if test "${with_yapr+set}" = set; then :
 		yap_cv_yapr=no
 	else
 		yap_cv_yapr=$with_yapr
-		YAPR_INCLUDES="-I${yap_cv_yapr}/share/R/include"
 	fi
 else
   yap_cv_yapr=no
@@ -4931,9 +4930,9 @@ then
   ENABLE_YAPR="@# "
 elif test -e "$srcdir"/packages/YapR/Makefile.in
 then
-  ENABLE_YAPR="@# "
-else
   ENABLE_YAPR=""
+else
+  ENABLE_YAPR="@# "
 fi
 
 if test "$yap_cv_clpbn_bp" = no
@@ -6276,7 +6275,18 @@ fi
 
 if test "$yap_cv_yapr" != "no"
 then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for main in -lR" >&5
+   if test "$yap_cv_yapr" = "yes"
+   then
+       case "$target_os" in
+	*darwin*)
+	YAPR_INCLUDES="-I/Library/Frameworks/R.framework/Headers"
+	EXTRA_LIBS_FOR_DLLS="$EXTRA_LIBS_FOR_DLLS -framework R -L /Library/Frameworks/R.framework/Libraries"
+	;;
+	**)
+	YAPR_INCLUDES="-I/usr/include/R -I/usr/share/R/include"
+	esac
+   fi
+   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for main in -lR" >&5
 $as_echo_n "checking for main in -lR... " >&6; }
 if ${ac_cv_lib_R_main+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -6313,45 +6323,6 @@ _ACEOF
 
   LIBS="-lR $LIBS"
 
-fi
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for main in -lRmath" >&5
-$as_echo_n "checking for main in -lRmath... " >&6; }
-if ${ac_cv_lib_Rmath_main+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lRmath  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-
-int
-main ()
-{
-return main ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_lib_Rmath_main=yes
-else
-  ac_cv_lib_Rmath_main=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_Rmath_main" >&5
-$as_echo "$ac_cv_lib_Rmath_main" >&6; }
-if test "x$ac_cv_lib_Rmath_main" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_LIBRMATH 1
-_ACEOF
-
-  LIBS="-lRmath $LIBS"
-
 fi
 
 fi
@@ -6432,7 +6403,7 @@ $as_echo "$yap_cv_odbc" >&6; }
 	then
 		YAP_EXTRAS="$YAP_EXTRAS -DMYDDAS_ODBC"
                 case "$target_os" in
-			*darwin9*)
+			*darwin*)
 			LIBS="$LIBS -lodbc -framework CoreFoundation"
 			;;
 			**)
diff --git a/configure.in b/configure.in
index 64858c402..d02bde7ae 100644
--- a/configure.in
+++ b/configure.in
@@ -187,7 +187,7 @@ AC_ARG_WITH(gmp,
 	[yap_cv_gmp=yes])
 
 AC_ARG_WITH(yapr,
-	[ --with-yapr[=DIR]           use GNU Multiple Precision in DIR],
+	[ --with-yapr[=DIR]           interface to R language, R installed in DIR],
 	if test "$withval" = yes; then
 		YAPR_INCLUDES="-I/usr/share/R/include"
 		yap_cv_yapr=yes
@@ -195,7 +195,6 @@ AC_ARG_WITH(yapr,
 		yap_cv_yapr=no
 	else
 		yap_cv_yapr=$with_yapr
-		YAPR_INCLUDES="-I${yap_cv_yapr}/share/R/include"
 	fi,
 	[yap_cv_yapr=no])
 
@@ -466,9 +465,9 @@ then
   ENABLE_YAPR="@# "
 elif test -e "$srcdir"/packages/YapR/Makefile.in
 then
-  ENABLE_YAPR="@# "
-else
   ENABLE_YAPR=""
+else
+  ENABLE_YAPR="@# "
 fi
 
 if test "$yap_cv_clpbn_bp" = no 
@@ -693,8 +692,19 @@ fi
 
 if test "$yap_cv_yapr" != "no"
 then
-  AC_CHECK_LIB(R,main)
-  AC_CHECK_LIB(Rmath,main)
+   if test "$yap_cv_yapr" = "yes"
+   then
+       case "$target_os" in
+	*darwin*)
+	YAPR_INCLUDES="-I/Library/Frameworks/R.framework/Headers"
+	EXTRA_LIBS_FOR_DLLS="$EXTRA_LIBS_FOR_DLLS -framework R -L /Library/Frameworks/R.framework/Libraries"
+	;;
+	**)		
+dnl one of the two may work (Fedora vs Ubuntu)
+	YAPR_INCLUDES="-I/usr/include/R -I/usr/share/R/include"
+	esac
+   fi
+   AC_CHECK_LIB(R,main)
 fi
 
 dnl if test "$yap_cv_cudd" != "no"
@@ -739,7 +749,7 @@ then
 	then
 		YAP_EXTRAS="$YAP_EXTRAS -DMYDDAS_ODBC"
                 case "$target_os" in
-			*darwin9*)
+			*darwin*)
 			LIBS="$LIBS -lodbc -framework CoreFoundation"
 			;;
 			**)