A module declaration collects and packages declarations of adt, functions, constants and simple types, and creates an interface with a name that serves to identify the type of the module. The syntax is

module-declaration:
	identifier : module { mod-member-listopt } ;

mod-member-list:
	mod-member
	mod-member-list mod-member

mod-member:
	identifier-list : function-type ;
	identifier-list : data-type ;
	adt-declaration ;
	identifier-list : con expression ;
	identifier-list : type type ;

Linear: module {
	setflags: fn (flag: int);
	TRUNCATE: con 1;
	Vector: adt {
		v: array of real;
		add: fn (v1: self Vector, v2: Vector): Vector;
		cross: fn (v1: self Vector, v2: Vector): Vector;
		dot: fn (v1: self Vector, v2: Vector);
		make: fn (a: array of real): Vector;
	};
	Matrix: adt {
		m: array of array of real;
		add: fn (m1: self Matrix, m2: Matrix): Matrix;
		mul: fn (m1: self Matrix, m2: Matrix): Matrix;
		make: fn (a: array of array of real): Matrix;
	};
};

	linearmodule:  Linear;

	linearmodule = load Linear "/usr/dmr/limbo/linear.dis";
	if (linearmodule == nil) {
		sys->print("Can't load Linear\n");
		exit;
	}

To initialize data declared as part of a module declaration, an assignment expression may be used at the top level. For example:

	implement testmod;
	testmod: module {
		num:	int;
	};
	. . .
	num = 5;