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;