This should do it for ranges

ranges.fs

    type Range(min: decimal,max: decimal) = 
        member this.min = min
        member this.max = max
        static member (*) (r: Range, d: decimal) = Range(r.min * d,r.max * d)
        static member (*) (d: decimal, r: Range) = r*d
        static member (/) (r: Range, d: decimal) = Range(r.min / d,r.max / d)
        static member (/) (d: decimal, r: Range) = r/d
        static member (+) (r: Range, d: decimal) = Range(r.min + d,r.max + d)
        static member (+) (d: decimal, r: Range) = r+d
        static member (-) (r: Range, d: decimal) = Range(r.min - d,r.max - d)
        static member (-) (d: decimal, r: Range) = r-d
        static member (*) (l: Range, r: Range) = Range(Seq.min [l.min;r.min], Seq.max [l.max;r.max])
        static member (/) (l: Range, r: Range) = Range(Seq.max [l.min;r.min], Seq.min [l.max;r.max])
        member this.bounded(d: decimal) = [Seq.max [this.min;d] ;this.max] |> Seq.min
        
    type Position(value: decimal, range: Range) =
        member this.value = value
        member this.range = range
        static member (*) (r:Position, d: decimal) = Position(r.range.bounded(r.value*d), r.range)
        static member (*) (d: decimal, r:Position) = r * d
        static member (/) (r:Position, d: decimal) = Position(r.range.bounded(r.value/d), r.range)
        static member (/) (d: decimal, r:Position) = r / d
        static member (+) (r:Position, d: decimal) = Position(r.range.bounded(r.value+d), r.range)
        static member (+) (d: decimal, r:Position) = r + d
        static member (-) (r:Position, d: decimal) = Position(r.range.bounded(r.value-d), r.range)
        static member (-) (d: decimal, r:Position) = r - d