make "a mdarray [10 10]

for [j 1 10] [for [i 1 10] [mdsetitem list :i :j :a (1 + random 20)]]

to until.20
  for [j 1 10] [
    for [i 1 10] [
      type mditem list :i :j :a
      type "| |
      if equal? 20 mditem list :i :j :a [stop]
    ]
    print "||
  ]
end
until.20