program= program_heading block '.' .
  identifier_list= NAME { ',' NAME } .
  program_heading= PROGRAM NAME '(' identifier_list ')' ';' .

  block= declaration_part statement_part .

    constant= [ '+' | '-' ] ( CONSTANT_NAME | NUMBER ) | STRING .

    type= simple_type | structured_type | TYPE_NAME .
      simple_type= constant '..' constant.
      structured_type= array_type | record_type .
        array_type= ARRAY '[' index_type { ',' index_type } ']' OF
            element_type .
          index_type= simple_type .
          element_type= type .
        record_type= RECORD field_list END .
          field_list= record_section { ';' record_section } .
            record_section= identifier_list ':' type .

    declaration_part= [ constant_definition_part ]
        [ type_definition_part ] [ variable_declaration_part ]
        procedure_and_function_declaration_part .
      constant_definition_part= CONST constant_definition ';'
          { constant_definition ';' } .
        constant_definition= NAME '=' constant .
      type_definition_part= TYPE type_definition ';' { type_definition ';' } .
        type_definition= NAME '=' type .
      variable_declaration_part= VAR variable_declaration ';'
          { variable_declaration ';' } .
        variable_declaration= identifier_list ':' type .
      procedure_and_function_declaration_part=
          { ( procedure_declaration | function_declaration ) ';' } .
        formal_parameter_list= '(' formal_parameter_section
            { ';' formal_parameter_section } ')' .
          formal_parameter_section= [ VAR ]identifier_list ':' parameter_type .
            parameter_type= TYPE_NAME .
        procedure_heading= PROCEDURE NAME [ formal_parameter_list ] .
        function_heading= FUNCTION NAME [ formal_parameter_list ] ':' result_type .
          result_type= TYPE_NAME .

        procedure_declaration= procedure_heading ';' block.
        function_declaration= function_heading ';'  block  .

    statement_part= BEGIN statement_sequence END .
      statement_sequence= statement { ';' statement } .

        expression= F .
        expression_list= expression { ',' expression } .

        variable_access= ACCESS_NAME { end_access } .
          end_access= { array_access | record_access | function_parameters } .
            array_access= '[' expression_list ']' .
            record_access= '.' variable_access .
            function_parameters= '(' [ expression_list ] ')' .

        actual_parameter_list= '(' expression { ',' expression } ')' .

        expression= simple_expression [ relational_operator simple_expression ] .
          relational_operator= '=' | '<>' | '<' | '<=' | '>' | '>=' .
          simple_expression= [ '+' | '-' ] term { addition_operator term } .
            addition_operator= '+' | '-' | OR .
            term= factor { multiplication_operator factor } .
              multiplication_operator= '*' | '/' | DIV | MOD | AND .
              factor= NUMBER | STRING | CONSTANT_NAME
                  | variable_access | function_designator
                  | '(' expression ')' | NOT factor .
                function_designator= FUNCTION_NAME [ actual_parameter_list ] .

        statement= ( simple_statement | structured_statement ) .
          simple_statement= [ assignment_statement | procedure_statement ] .
            assignment_statement= ( variable_access | FUNCTION_NAME ) ':=' expression .
            procedure_statement= PROCEDURE_NAME [ actual_parameter_list ] .
          structured_statement= compound_statement | repetitive_statement
              | conditional_statement .
            compound_statement= BEGIN statement_sequence END .
            repetitive_statement= while_statement | repeat_statement
                | for_statement .
              while_statement= WHILE expression DO statement .
              repeat_statement= REPEAT statement_sequence UNTIL expression .
              for_statement= FOR VARIABLE_NAME ':=' initial_expression
                  ( TO | DOWNTO ) final_expression DO statement .
                initial_expression= expression .
                final_expression= expression .
            conditional_statement= if_statement | case_statement .
              if_statement= IF expression THEN statement [ ELSE statement ] .
              case_statement= CASE expression OF
                  case_element { ';' case_element } [ ';' ] END .
                case_element= case_label_list ':' statement .
                  case_label_list= constant { ',' constant } .
.