function 3: arithmetic

arithmetic:
    description:
        arithmetic(one, symbol, two)
        one and two are converted to kets (for now), and then processed using the symbol type
        possible types are: + - * / % ^
        ie, addition, subtraction, multiplication, division, modulus, power
        Note that categories are preserved, and if the categories differ, return the empty ket |>
        If one of the kets has a category, and the other doesn't, then the result will have that category too
        now implemented as: (one ++ two), (one -- two), (one ** two), (one // two), (one %% two), (one ^^ two)

    examples:
        arithmetic(|2>, |+>, |3>)
            |5>

        arithmetic(|2>, |*>, |3>)
            |6>

        (|number: 2> ++ |number: 7>)
            |number: 9>

        (|23> %% |7>)
            |2>

    see also: