modeltype e uses ecore('http://www.eclipse.org/emf/2002/Ecore');

transformation bug415024();

main() {
	var t := Tuple {a = Set{1}, b = List{1}};

	// syntax error expected because 'a' is immutable
	//t.a += 3;
	
	// no syntax error expected because 'b' is mutable
	t.b += 3;
	assert fatal (t.b = List{1,3});

	map m();
}

mapping m() : r1 : List(EPackage), r2 : EPackage {
	init {
		r1 += object EPackage{};
	}
	
	assert fatal (r1->size() = 1);
	assert fatal (r1 = result.r1);

	r1 += object EPackage{};

	assert fatal (r1->size() = 2);
	assert fatal (r1 = result.r1);

	result.r1 += object EPackage{};

	assert fatal (r1->size() = 3);
	assert fatal (r1 = result.r1);

}