Q:  I am migrating from VB. Where is the exponent function?

A: There isn't one, but it is simple to make one using Ln().  Ln() gives us the natural logarithm of a number.  Using that, we can get the exponentiation easily. E.g.  If we want X^Y (or  X to the Y power) we would write the code like this:

   ExpXY := Exp(Ln(X) * Y);

To use a generic function, declare the formal parameters and function result as Extended, and the conversions from the actual parameters and back to your result variable will be done automatically.  (Ln is the natural logarithm of a number).

{ Reproduced from post by Dr. Bob }
  function SwartPower(X: LongInt; N: Word): LongInt;
  var R: LongInt;
  begin
    if N = 0 then SwartPower := 1
    else
    begin
      if N = 1 then SwartPower := X
      else
      begin
        if Odd(N) then
        begin
          R := X;
          Dec(N)
        end
        else R := 1;

        while N > 1 do { inner loop O(log N) }
        begin
          if Odd(N) then R := R * X;
          X := X * X;
          N := N div 2
        end;

        if R > 1 then
          SwartPower := R * X
        else { save last multiplication with 1 }
          SwartPower := X
      end
    end
  end {SwartPower};