knob trim property

when plugging a cable into a knob, how should the knob behave?

add

min, max, freq, add, subtract, wrap:min, wrap:max, mix:interp, clamp:min, clamp:max, fold:min, fold:max, sah:thresh, gt/lt/gte/lte/etc, train:freq, train:width, phasor, cycle,

mul

rate, mul, div, eq, neq (etc), mul, round

in the case of the subtract op

    "sub": {
        "classification": "mathemagical",
        "inputs": {
            "value1": {
                "info": "input value 1",
                "value": 0,
                "range": [
                    -1,
                    1
                ],
                "kind": "inlet"
            },
            "value2": {
                "info": "input value 2",
                "value": 0,
                "range": [
                    0,
                    1
                ],
                "kind": "knob",
                "trim": "add" <<<<< right here
            }
        },
        "outputs": {
            "difference": "in1 - in2"
        },
        "sign": "subtract"
    }