FUNCTION farey (n, dsc)
    b = 1: c = 1: d = n

    IF dsc = TRUE THEN a = 1: c = n - 1

    cnt = cnt + 1
    IF n < 12 THEN PRINT a; "/"; b;

    WHILE ((c <= n) AND NOT dsc) OR ((a > 0) AND dsc)
	aa = a: bb = b: cc = c: dd = d
	k = (n + b) \ d
	a = cc: b = dd: c = k * cc - aa: d = k * dd - bb
	cnt = cnt + 1
	IF n < 12 THEN PRINT a; "/"; b;
    WEND

    IF n < 12 THEN PRINT

    farey = cnt
END FUNCTION

CLS
CONST TRUE = -1: FALSE = NOT TRUE

FOR i = 1 TO 9
    PRINT USING "F# ="; i;
    t = farey(i, FALSE)
NEXT i
FOR i = 10 TO 11
    PRINT USING "F## ="; i;
	t = farey(i, FALSE)
NEXT i
PRINT
FOR i = 100 TO 900 STEP 100
    PRINT USING "F#### = ######"; i; farey(i, FALSE)
NEXT i
PRINT USING "F1000 = ######"; farey(1000, FALSE)