Editing MAD (programming language) (section)

== Operator definition and redefinition ==
One of the most interesting features in MAD is the ability to extend the language by redefining existing operators, defining new operators, or defining new data types (modes). The definitions are made using MAD declaration statements and assembly language mnemonics included following the declaration up to the END pseudo-instruction that implement the operation.

* DEFINE BINARY OPERATOR ''defined-op'', PRECEDENCE ''rank'' ''existing-op'' MODE STRUCTURE ''mode-options''
* DEFINE UNARY OPERATOR ''defined-op'', PRECEDENCE ''rank'' ''existing-op'' MODE STRUCTURE ''mode-options''
* MODE STRUCTURE ''mode-no'' = ''mode-no'' ''existing-op'' ''mode-no''
* MODE STRUCTURE ''mode-no'' = ''mode-no'' ''existing-op'' ''mode-no'' SAME SEQUENCE AS ''mode-no'' ''existing-op'' ''mode-no''

where:
* ''rank'' is one of SAME AS, LOWER THAN, or HIGHER THAN; and
* ''mode-options'' are the options that appear on the MODE STRUCTURE statement.

Three pre-defined packages of definitions (MATRIX, DOUBLE PRECISION, and COMPLEX) are available for inclusion in MAD source programs using the INCLUDE statement.

* INCLUDE ''package''