CLS
PRINT "  +----------------------------------------------+  "
PRINT "  |                                              |  "
PRINT "  |          MATHEMATICAL UTILITIES              |  "
PRINT "  |                                              |  "
PRINT "  |      Copy any functions you need into        |  "
PRINT "  |            your own programs.                |  "
PRINT "  |                                              |  "
PRINT "  |                                              |  "
PRINT "  |  max (a, b)  - The larger of two numbers     |  "
PRINT "  |  min (a, b)  - The smaller of two numbers    |  "
PRINT "  |  fib (n)     - Nth fibonacci number          |  "
PRINT "  |  fact (n)    - The factorial of N            |  "
PRINT "  |  gcd (a, b)  - The greatest common           |  "
PRINT "  |                   divisor of A and B         |  "
PRINT "  |                                              |  "
PRINT "  +----------------------------------------------+  "'


// Maximum/minimum

FUNC max (a, b) CLOSED
    IF a > b THEN
        RETURN a
    ELSE
        RETURN b
    ENDIF
ENDFUNC max

FUNC min (a, b) CLOSED
    IF a < b THEN
        RETURN a
    ELSE
        RETURN b
    ENDIF
ENDFUNC min


// Fibonacci sequence

FUNC fib (n) CLOSED
    f1 := 0
    f2 := 1
    FOR i := 1 TO n DO
        f3 := f1 + f2
        f1 := f2
        f2 := f3
    NEXT i
    RETURN f1
ENDFUNC fib


// Factorial function

FUNC fact (n) CLOSED
    result := 1
    FOR i := 2 TO n DO
        result := result * i
    NEXT i
    RETURN result
ENDFUNC fact


// Greatest common divisor (using "Euclid's algorithm")

FUNC gcd (a, b) CLOSED
    IF b = 0 THEN
        RETURN a
    ELSE
        RETURN gcd (b, a MOD b)
    ENDIF
ENDFUNC gcd