Add authors and licence to YARS-PG in EBNF notation

Author: lszeremeta

other-notations/YARSpg.ebnf

@@ -1,8 +1,33 @@
-/* YARS-PG grammar in Extended Backus-Naur Form (EBNF) notation
-   Based on YARS-PG grammar in ANTLR4
-   
-   See more at:
-   https://github.com/lszeremeta/antlr-yarspg
+/*
+ YARS-PG grammar in Extended Backus-Naur Form (EBNF) notation
+ Based on YARS-PG grammar in ANTLR4
+ 
+ See more at:
+ https://github.com/lszeremeta/antlr-yarspg
+ 
+ [The "BSD licence"]
+ Copyright (c) 2018, Łukasz Szeremeta (@ University of Bialystok, http://www.uwb.edu.pl/)
+ Copyright (c) 2018, Dominik Tomaszuk (@ University of Bialystok, http://www.uwb.edu.pl/)
+ Copyright (c) 2018, Karol Litman (@ University of Bialystok, http://www.uwb.edu.pl/)
+ All rights reserved.
+
+ Based on YARS grammar
+ (https://github.com/lszeremeta/antlr-yars/blob/master/yars/YARS.g4)
+ distributed under BSD licence.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+ 1. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in the
+    documentation and/or other materials provided with the distribution.
+ 3. The name of the author may not be used to endorse or promote products
+    derived from this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 */
 
 yarspg   ::= ( statement NL+ )*