Vector objects

function DotProduct(a,b){

return a.x*b.x + a.y*b.y;

}

function Scale(a, s){

return [x->a.x*s, y->a.y*s];

}

Test.AreEqual(19, DotProduct([x->1, y->3], [x->4, y->5]));

Test.AreEqual(5.1, Scale([x->0.51, y->3], 10).x);