void local fn MertensFunction
  long mertens(1000), n, k, crossesTotal = 0, zerosTotal = 0

  mertens(1) = 1

  for n = 2 to 1000
    mertens(n) = 1
    for k = 2 to n
      mertens(n) = mertens(n) - mertens(n/k)
    next
  next

  printf @"First 99 Mertens numbers:\n    \b"

  for n = 1 to 99
    printf @"%3ld \b", mertens(n)
    if ( n mod 10 == 9 ) then print
  next

  for n = 1 to 1000
    if ( mertens(n) == 0 )
      zerosTotal++
      if mertens(n-1) != 0 then crossesTotal++
    end if
  next

  print
  printf @"mertens(n) array is zero %ld times.", zerosTotal
  printf @"mertens(n) array crosses zero %ld times.", crossesTotal
end fn

fn MertensFunction

HandleEvents