I would retort with: Packages are too big to make into a functional dependency. In the end, in this functions-as-dependencies world, a trig package would be something like:

    (name) => 
        switch (name) {
            case 'sin': 
               (x) => sin(x);
               break;
            case 'cos':
               (x) => cos(x);
               break;
        }