RosettaCodeData/Task/Ackermann-function/FALSE/ackermann-function.false

[$$[%
  \$$[%
     1-\$@@a;!  { i j -> A(i-1, A(i, j-1)) }
  1]?0=[
     %1         { i 0 -> A(i-1, 1) }
   ]?
  \1-a;!
1]?0=[
  %1+           { 0 j -> j+1 }
 ]?]a: { j i }

3 3 a;! .  { 61 }