group identifier is ( entity_class_entry_list ) ;
entity_class_entry { , entity_class_entry }
entity_class [ <> ]
Groups of this type consist of two signals.
GROUP pin2pin IS ( SIGNAL , SIGNAL ) ;
Groups of this type consist of any number of signals.
GROUP pin_set IS ( SIGNAL <>) ;
Groups of this type consist of any number of files.
GROUP file_groups IS ( FILE <>) ;
Groups of this type consist of any number of groups.
GROUP gog IS ( GROUP <>) ;