C# library overloads ^ operator. How to use ** instead?

Question

The Symbolism library overloads arithmetic operators. Although it's written in C# I can use it from F#: ``` open Symbolism let x = new Symbol("x") let y = new Symbol("y") let z = new Symbol("z") printfn "%A" (2*x + 3 + 4*x + 5*y + z + 8*y) ``` the output: ``` 3 + 6 * x + 13 * y + z ``` However, it also overloads `^` for powers. This of course doesn't play well with F#. As a step towards a workaround, I exported a method group for powers: ``` printfn "%A" (Aux.Pow(x, 2) * x) ``` output: ``` x ^ 3 ``` How can I overload `**` to use the `Aux.Pow` method group instead? I can do something like this: ``` let ( ** ) (a: MathObject) (b: MathObject) = Aux.Pow(a, b) ``` And that does work for `MathObject` values: ``` > x ** y * x;; val it : MathObject = x ^ (1 + y) ``` But `Aux.Pow` is overloaded for `int` as well: ``` public static MathObject Pow(MathObject a, MathObject b) { return new Power(a, b).Simplify(); } public static MathObject Pow(MathObject a, int b) { return a ^ new Integer(b); } p…

Accepted Answer

You can use the trick described here like this:

```
open Symbolism

type MathObjectOverloads =
    | MathObjectOverloads 
    static member (?<-) (MathObjectOverloads, a: #MathObject, b: int) = MathObject.op_ExclusiveOr(a, b)
    static member (?<-) (MathObjectOverloads, a: #MathObject, b: #MathObject) = MathObject.op_ExclusiveOr(a, b)
    static member (?<-) (MathObjectOverloads, a: System.Int32, b: #MathObject) = MathObject.op_ExclusiveOr(a, b)

let inline ( ** ) a b = (?<-) MathObjectOverloads a b

let two = Integer(2)
let three = Integer(3)

two ** three

two ** 3

2 ** three
```

Unlike in the linked answer, we have to use the (?<-) operator because it's the only operator that can take 3 arguments instead of 2, and we need to overload on both the left and right side of the ^ operator

C# library overloads ^ operator. How to use ** instead?

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