RosettaCodeData/Task/Fibonacci-sequence/Simula/fibonacci-sequence.simula

INTEGER PROCEDURE fibonacci(n);
INTEGER n;
BEGIN
    INTEGER lo, hi, temp, i;
    lo := 0;
    hi := 1;
    FOR i := 1 STEP 1 UNTIL n - 1 DO
    BEGIN
        temp := hi;
        hi := hi + lo;
        lo := temp
    END;
    fibonacci := hi
END;