extern
function exp ( x : real ): real;
 
const
factor2 = 0.50000000000000e+00;
factor3 = 0.16666666666667e+00;
factor4 = 0.41666666666667e-01;
factor5 = 0.83333333333333e-02;
factor6 = 0.13888888888889e-02;
factor7 = 0.19841269841270e-03;
factor8 = 0.24801587301587e-04;
factor9 = 0.27557319223986e-05;
factor10 = 0.27557319223986e-06;
factor11 = 0.25052108385442e-07;
factor12 = 0.20876756987868e-08;
factor13 = 0.16059043836822e-09;
factor14 = 0.11470745597730e-10;
factor15 = 0.76471637318198e-12;
factor16 = 0.47794773323874e-13;
factor17 = 0.28114572543455e-14;
factor18 = 0.15619206968586e-15;
factor19 = 0.82206352466245e-17;
factor20 = 0.41103176233122e-18;
factor21 = 0.19572941063392e-19;
 
type
str = array [1..22] of char;
 
var
result,xa : real;
p : array [1..21] of real;
count,i,j : integer;
sign : char;
 
begin (* exp *)
 
if x >145.0 then exp:=0.99999999999999e+63
  else if x < -145.0 then exp:=0.0
else
begin
 
if x < 0.0 then
  begin
  sign:='-';
  x:=-x;
  end
else sign:='+';
 
(* compute exp(x) for 0<x<1.5 *)
count:=0;
if x > 1.5 then
  if x < 6.0 then begin count:=1; x:=x/4 end
  else if x < 24.0 then begin count:=2; x:=x/16 end
       else if x < 96.0 then
		begin count:=3; x:=x/64 end
            else begin count:=4; x:=x/256.0 end;
 
if x < 0.007 then
  result:=x+1.0
else
begin
xa:=x;
for i:=1 to 21 do
  begin
  p[i]:=xa;
  xa:=xa*x;
  end;
 
result:=
	1+x
	+(p[2]*factor2)
	+(p[3]*factor3)
	+(p[4]*factor4)
	+(p[5]*factor5)
	+(p[6]*factor6)
	+(p[7]*factor7)
	+(p[8]*factor8)
	+(p[9]*factor9)
	+(p[10]*factor10)
	+(p[11]*factor11)
	+(p[12]*factor12)
	+(p[13]*factor13)
	+(p[14]*factor14)
	+(p[15]*factor15)
	+(p[16]*factor16)
	+(p[17]*factor17)
	+(p[18]*factor18);
 
end; (* else *)
for i:=1 to count do result:=sqr( sqr(result) );
 
if sign = '-' then exp:=1.0/result else exp:=result;
 
end; (* else *)
 
end; (* exp *).