other_boolean_form ::= 
 {collection_name . EXISTS (index)
 | {cursor_name
   | cursor_variable_name
   | :host_cursor_variable_name
   | SQL} % {FOUND | ISOPEN | NOTFOUND}
 | expression {relational_operator expression
              | IS [NOT] NULL
              | [NOT] LIKE pattern
              | [NOT] BETWEEN expression AND expression
              | [NOT] IN (expression [, expression]...)}}

character_expression ::=
 {character_constant_name
 | character_function_call
 | character_literal
 | character_variable_name
 | :host_variable_name [:indicator_name]}
 [|| {character_constant_name
     | character_function_call
     | character_literal
     | character_variable_name
     | : host_variable_name [:indicator_name]} 
 [|| {character_constant_name
     | character_function_call
     | character_literal
     | character_variable_name
     | : host_variable_name [:indicator_name]}]...