$ 'main' (--)
 \  Read m and n as input. Just one number each for now
  \  Input is in the form "m\rn" where \r is a return character
   \-[Enter m: ]oi(!m!)[\n\]o-[Enter n: ]oii(!n!)[\n\]o-----(n)-(m)-{ackermann}-[): ](n)[,](m)[A(]oooooo--#


$ 'ackermann' (n m -- A(m,n))  A(m,n) = n+1             if m=0
 \                                    = A(m-1,1)        if m>0 and n=0
  \                                   = A(m-1,A(m,n-1)) if m>0 and n>0
   \-(!m!)-(!n!)-\
                 | 
                 /
      /---q(m)0--     
      |
     t^f        f/-(n)1s-(m)-{ackermann}-(m)1s-{ackermann}-#  
     / \-(n)0q--<
     |          t\-1-(m)1s-{ackermann}-#
     \-(n)1a-#