5.2.1. Logical Term

5.2.1. Logical Term
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	Description
	A logical term is an ASM term that evaluates to a boolean value. It can be either a simple or a compound expression.

Syntax

	Syntax
LogicalTermAST ::= LogicalAndTermAST \| LogicalTermAST \|\| LogicalAndTermAST \| LogicalTermAST xor LogicalAndTermAST A logical term can be a compound expression, i.e. it can be composed of conjunctive logical terms with a logical OR operation. The logical OR operator can be either the `\|\|` (OR) or the `xor` operator; these are interpreted in the classical way.

LogicalTermAST ::= LogicalAndTermAST 
                 | LogicalTermAST || LogicalAndTermAST
	               | LogicalTermAST xor LogicalAndTermAST

A logical term can be a compound expression, i.e. it can be composed of conjunctive logical terms with a logical OR operation.

The logical OR operator can be either the || (OR) or the xor operator; these are interpreted in the classical way.

Semantics

Logical operations are defined only for Boolean and Multiplicity types.

The interpretation of operations is trivial in case of Booleans.

A Multiplicity value is handled as a pair of boolean values: one denotes if source can be multiple or not, whereas the other denotes it for the target of the relation. Logical operations on Multiplicity values are performed separately for the first and second parts of the pairs. The result is a Multiplicity value.

Table 2.3. Logical operators (AND, OR, XOR)

	Undef	Boolean	String	Integer	Double	ModelElement	Multiplicity
Undef	Undef	Undef	Undef	Undef	Undef	Undef	Undef
Boolean	Undef	Bool
String	Undef
Integer	Undef
Double	Undef
ModelElement	Undef
Multiplicity	Undef						Multi

	Warning
	Note that the evaluation rules of boolean operators changed in the new release to be compliant with its use in Java.

Defined In: term

Used By: base logical term, check condition, if rule