Index: config.h.in
===================================================================
RCS file: /cvsroot/gnugo/gnugo/config.h.in,v
retrieving revision 1.17
diff -u -r1.17 config.h.in
--- config.h.in	26 Sep 2002 22:28:06 -0000	1.17
+++ config.h.in	28 Sep 2002 22:01:43 -0000
@@ -30,6 +30,9 @@
 /* Semeai module. Default standard. */
 #undef EXPERIMENTAL_SEMEAI
 
+/* GAIN/LOSS codes module. Default disabled. */
+#undef EXPERIMENTAL_OWL_EXT
+
 /* Give the directory where gnugo was compiled */
 #undef GNUGO_PATH
 
Index: config.vcin
===================================================================
RCS file: /cvsroot/gnugo/gnugo/config.vcin,v
retrieving revision 1.15
diff -u -r1.15 config.vcin
--- config.vcin	5 Jun 2002 21:45:36 -0000	1.15
+++ config.vcin	28 Sep 2002 22:01:43 -0000
@@ -30,6 +30,9 @@
 /* Semeai module. Default standard. */
 #define EXPERIMENTAL_SEMEAI 0
 
+/* GAIN/LOSS codes. Disabled by default. */
+#define EXPERIMENTAL_OWL_EXT 0
+
 /* Define as 1 to use the grid optimisation, or 2 to run it in self-test mode
    */
 #define GRID_OPT 1
Index: configure
===================================================================
RCS file: /cvsroot/gnugo/gnugo/configure,v
retrieving revision 1.61
diff -u -r1.61 configure
--- configure	25 Sep 2002 11:52:04 -0000	1.61
+++ configure	28 Sep 2002 22:01:45 -0000
@@ -1411,6 +1411,12 @@
 
 fi;
 
+# Check whether --enable-experimental-owl-ext or --disable-experimental-owl-ext was given.
+if test "${enable_experimental_owl_ext+set}" = set; then
+  enableval="$enable_experimental_owl_ext"
+
+fi;
+
 # Check whether --enable-experimental-reading or --disable-experimental-reading was given.
 if test "${enable_experimental_reading+set}" = set; then
   enableval="$enable_experimental_reading"
@@ -4795,6 +4801,18 @@
 else
    cat >>confdefs.h <<\EOF
 #define EXPERIMENTAL_SEMEAI 0
+EOF
+
+fi
+
+if test "$enable_experimental_owl_ext" = "yes" ; then
+   cat >>confdefs.h <<\EOF
+#define EXPERIMENTAL_OWL_EXT 1
+EOF
+
+else
+   cat >>confdefs.h <<\EOF
+#define EXPERIMENTAL_OWL_EXT 0
 EOF
 
 fi
Index: configure.in
===================================================================
RCS file: /cvsroot/gnugo/gnugo/configure.in,v
retrieving revision 1.62
diff -u -r1.62 configure.in
--- configure.in	25 Sep 2002 11:52:04 -0000	1.62
+++ configure.in	28 Sep 2002 22:01:45 -0000
@@ -78,6 +78,10 @@
  [  --enable-experimental-semeai    use the experimental semeai module
   --disable-experimental-semeai    use standard semeai module (default)])
 
+AC_ARG_ENABLE(experimental-owl-ext,
+ [  --enable-experimental-owl-ext    use the experimental GAIN/LOSS codes
+  --disable-experimental-owl-ext    use standard owl module (default)])
+
 AC_ARG_ENABLE(experimental-reading,
  [  --enable-experimental-reading    use experimental pattern-based reading
   --disable-experimental-reading    use standard reading (default)])
@@ -392,6 +396,17 @@
    AC_DEFINE(EXPERIMENTAL_SEMEAI, 1)
 else
    AC_DEFINE(EXPERIMENTAL_SEMEAI, 0)
+fi
+
+dnl ------------ Owl extensions ------------
+
+AH_TEMPLATE([EXPERIMENTAL_OWL_EXT],
+[GAIN/LOSS codes. Disabled by default.])
+
+if test "$enable_experimental_owl_ext" = "yes" ; then
+   AC_DEFINE(EXPERIMENTAL_OWL_EXT, 1)
+else
+   AC_DEFINE(EXPERIMENTAL_OWL_EXT, 0)
 fi
 
 dnl ------------ Reading -------------------
Index: makevcdist.pl
===================================================================
RCS file: /cvsroot/gnugo/gnugo/makevcdist.pl,v
retrieving revision 1.6
diff -u -r1.6 makevcdist.pl
--- makevcdist.pl	5 Jun 2002 21:45:36 -0000	1.6
+++ makevcdist.pl	28 Sep 2002 22:01:45 -0000
@@ -13,6 +13,7 @@
    DEFAULT_SEMEAI_VARIATIONS => 250,
    OWL_NODE_LIMIT => 1000,
    EXPERIMENTAL_SEMEAI => 0,
+   EXPERIMENTAL_OWL_EXT => 0,
    EXPERIMENTAL_CONNECTIONS => 0,
    EXPERIMENTAL_INFLUENCE => 1,
    EXPERIMENTAL_READING => 0,
Index: engine/globals.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/globals.c,v
retrieving revision 1.29
diff -u -r1.29 globals.c
--- engine/globals.c	16 Sep 2002 07:27:48 -0000	1.29
+++ engine/globals.c	28 Sep 2002 22:01:46 -0000
@@ -132,6 +132,8 @@
 /* use alternate connection reading algorithm */
 int alternate_connections = ALTERNATE_CONNECTIONS;
 int owl_threats = OWL_THREATS;          /* compute owl threats */
+/* use experimental owl extension (GAIN/LOSS) */
+int experimental_owl_ext = EXPERIMENTAL_OWL_EXT;
 
 int allow_suicide       = 0;    /* allow opponent to make suicide moves */
 int capture_all_dead    = 0;    /* capture all dead opponent stones */
Index: engine/gnugo.h
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/gnugo.h,v
retrieving revision 1.69
diff -u -r1.69 gnugo.h
--- engine/gnugo.h	22 Sep 2002 11:50:05 -0000	1.69
+++ engine/gnugo.h	28 Sep 2002 22:01:46 -0000
@@ -268,6 +268,7 @@
 extern float lower_bound;
 extern float upper_bound;
 extern int chinese_rules;       /* use chinese (area) rules for counting */
+extern int experimental_owl_ext;     /* use experimental owl (GAIN/LOSS) */
 extern int experimental_semeai;      /* use experimental semeai module */
 extern int experimental_connections; /* use experimental connection module */
 extern int alternate_connections;    /* use alternate connection module */
Index: interface/main.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/interface/main.c,v
retrieving revision 1.53
diff -u -r1.53 main.c
--- interface/main.c	22 Sep 2002 11:50:05 -0000	1.53
+++ interface/main.c	28 Sep 2002 22:01:51 -0000
@@ -82,6 +82,7 @@
       OPT_DECIDE_SEMEAI,
       OPT_DECIDE_TACTICAL_SEMEAI,
       OPT_EXPERIMENTAL_SEMEAI,
+      OPT_EXPERIMENTAL_OWL_EXT,
       OPT_SEMEAI_VARIATIONS,
       OPT_EXPERIMENTAL_CONNECTIONS,
       OPT_EXPERIMENTAL_INFLUENCE,
@@ -203,6 +204,7 @@
   {"chinese-rules",  no_argument,       0, OPT_CHINESE_RULES},
   {"japanese-rules", no_argument,       0, OPT_JAPANESE_RULES},
   {"experimental-semeai",  no_argument, 0, OPT_EXPERIMENTAL_SEMEAI},
+  {"experimental-owl-ext",  no_argument, 0, OPT_EXPERIMENTAL_OWL_EXT},
   {"semeai-variations",   required_argument, 0, OPT_SEMEAI_VARIATIONS},
   {"experimental-connections",  no_argument, 0, OPT_EXPERIMENTAL_CONNECTIONS},
   {"owl-threats",     no_argument,      0, OPT_OWL_THREATS},
@@ -316,6 +318,7 @@
     owl_threats = 1;
   else
     owl_threats = 0;
+  experimental_owl_ext = EXPERIMENTAL_OWL_EXT;
   experimental_semeai = EXPERIMENTAL_SEMEAI;
   experimental_connections = EXPERIMENTAL_CONNECTIONS;
 
@@ -413,6 +416,9 @@
 	if (EXPERIMENTAL_SEMEAI)
 	  fprintf(stderr,
 		  "configure option enabled: experimental semeai\n");
+	if (EXPERIMENTAL_OWL_EXT)
+	  fprintf(stderr,
+		  "configure option enabled: experimental GAIN/LOSS codes\n");
 	if (EXPERIMENTAL_READING)
 	  fprintf(stderr,
 		  "configure option enabled: experimental reading\n");
@@ -483,6 +489,10 @@
 
       case OPT_JAPANESE_RULES: 
 	chinese_rules = 0;
+	break;
+
+      case OPT_EXPERIMENTAL_OWL_EXT:
+	experimental_owl_ext = 1;
 	break;
 
       case OPT_EXPERIMENTAL_SEMEAI: