function power(base:double;exponent:integer):double;
 begin
  if exponent<0 then pow:=1/pow(base,-exponent)
  else if exponent=0 then pow:=1
  else pow:=base*pow(base,pred(exponent));
 end;

function power(base:double;exponent:integer):double;
  begin
   if exponent<0 then pow:=1/pow(base,-exponent)
   else if exponent=0 then pow:=1
   else pow:=base*pow(base,pred(exponent));
  end;
 

function power ( base : double; exponent : integer ) : double;

  begin
    if exponent < 0 then
      power := 1.0 / power( base, -exponent )
    else
      if exponent = 0 then
        power := 1
      else
        power := base * power( base, pred( exponent ) )
  end;

{ power check for checking the base and exponent in a recursive routine

  by Carl W. Skipworth  Rev Date 2013-Mar-3

}
program powercheck;

  uses
    Crt;

  var
    base : double;
    exp  : integer;
    value : double;

{$include power.pas}

  begin
    writeln( 'Power number check for 2' );
    base := 2.0;

    for exp := -5 to 20 do begin
      value := power( base, exp );
      writeln( 'exp is', exp:4, ' value is', value:15:6 )
    end;

  end.