expression

expression ::= 
      relation { "and" relation } | relation { "and" "then" relation } 
      | relation { "or" relation } | relation { "or" "else" relation } 
      | relation { "xor" relation } 

This rule is called by

-> ancestor_part
-> array_component_association
-> assignment_statement
-> at_clause
-> attribute_definition_clause
-> attribute_designator
-> case_statement
-> condition
-> decimal_fixed_point_definition
-> default_expression
-> delay_relative_statement
-> delay_until_statement
-> digits_constraint
-> discrete_choice
-> discriminant_association
-> entry_index
-> floating_point_definition
-> generic_association
-> indexed_component
-> integer_type_definition
-> number_declaration
-> object_declaration
-> ordinary_fixed_point_definition
-> parameter_association
-> positional_array_aggregate
-> pragma_argument_association
-> primary
-> qualified_expression
-> range_attribute_designator
-> record_component_association
-> restriction
-> return_statement
-> static_expression
-> type_conversion