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Operators must be defined on values of specific types. For instance, + is defined on numbers, but not on structures. Operators are often defined on groups of types. For the purposes of Modula-2, the following definitions hold:

The following operators are supported, and appear in order of increasing precedence:

Function argument or array index separator.

Assignment. The value of var := value is value.

<, >
Less than, greater than on integral, floating-point, or enumerated types.

<=, >=
Less than, greater than, less than or equal to, greater than or equal to on integral, floating-point and enumerated types, or set inclusion on set types. Same precedence as <.

=, <>, #
Equality and two ways of expressing inequality, valid on scalar types. Same precedence as <. In GDB scripts, only <> is available for inequality, since # conflicts with the script comment character.

Set membership. Defined on set types and the types of their members. Same precedence as <.

Boolean disjunction. Defined on boolean types.

AND, &
Boolean conjuction. Defined on boolean types.

The GDB "artificial array" operator (see section Expressions).

+, -
Addition and subtraction on integral and floating-point types, or union and difference on set types.

Multiplication on integral and floating-point types, or set intersection on set types.

Division on floating-point types, or symmetric set difference on set types. Same precedence as *.

Integer division and remainder. Defined on integral types. Same precedence as *.

Negative. Defined on INTEGER and REAL data.

Pointer dereferencing. Defined on pointer types.

Boolean negation. Defined on boolean types. Same precedence as ^.

RECORD field selector. Defined on RECORD data. Same precedence as ^.

Array indexing. Defined on ARRAY data. Same precedence as ^.

Procedure argument list. Defined on PROCEDURE objects. Same precedence as ^.

::, .
GDB and Modula-2 scope operators.

Warning: Sets and their operations are not yet supported, so GDB treats the use of the operator IN, or the use of operators +, -, *, /, =, , <>, #, <=, and >= on sets as an error.

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