real procedure FRESNELCOS(u);
   real u;
begin
   integer N;
   real pi2, x, xsqr, term, frcoi, frcos;
   pi2 ≔ 1·5707963;
   x ≔ pi2 × (u⭡2);
   frcos ≔ 1;
   xsqr ≔ x⭡2;
   N ≔ 3;
   term ≔ -xsqr/2;
   frcoi ≔ 1 + (term/5);
   Loop: if frcoi = frcos then go to exit;
   term ≔ - term × xsqr/((2×N-2) × (2×N-3));
   frcos ≔ frcoi;
   frcoi ≔ frcos + term/(4×N - 3);
   N ≔ N + 1;
   go to Loop;
   exit: FRESNELCOS ≔ u × frcos
end FRESNELCOS;