diff --git a/thun/gnu-prolog/meta-defs.pl b/thun/gnu-prolog/meta-defs.pl
index e7a49fd..35326ec 100644
--- a/thun/gnu-prolog/meta-defs.pl
+++ b/thun/gnu-prolog/meta-defs.pl
@@ -1,4 +1,21 @@
 /*
+    Copyright  2019 Simon Forman
+
+    This file is part of Thun
+
+    Thun is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Thun is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Thun.  If not see <http://www.gnu.org/licenses/>.
+
 Definitions
 */
 
diff --git a/thun/gnu-prolog/meta-math.pl b/thun/gnu-prolog/meta-math.pl
index 3ac327f..c706806 100644
--- a/thun/gnu-prolog/meta-math.pl
+++ b/thun/gnu-prolog/meta-math.pl
@@ -1,4 +1,21 @@
 /*
+    Copyright  2019 Simon Forman
+
+    This file is part of Thun
+
+    Thun is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Thun is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Thun.  If not see <http://www.gnu.org/licenses/>.
+
 
 To handle comparision operators the possibility of exceptions due to
 insufficiently instantiated arguments must be handled.  First try to make
diff --git a/thun/gnu-prolog/parser.pl b/thun/gnu-prolog/parser.pl
index 4258f89..ab43ac7 100644
--- a/thun/gnu-prolog/parser.pl
+++ b/thun/gnu-prolog/parser.pl
@@ -1,5 +1,5 @@
 /*
-    Copyright  2018, 2019 Simon Forman
+    Copyright  2019 Simon Forman
 
     This file is part of Thun