plsql_block

plsql_block 
      ::= 
      [ "<<" label_name ">>" ] 
      [ "declare" declare_spec { declare_spec } ] 
      "begin" 
      seq_of_statements 
      [ "exception" exception_handler { exception_handler } ] 
      "end" [ label_name ] ";" 

This rule is call by

-> create_trigger
-> statement