A-M baby

Task/Ackermann-function/Maple/ackermann-function-3.maple

@@ -0,0 +1,16 @@
+Ackermann := proc( m :: nonnegint, n :: nonnegint )
+  option remember; # optional automatic memoization
+  if m = 0 then
+    n + 1
+  elif m = 1 then
+    n + 2
+  elif m = 2 then
+    2 * n + 3
+  elif m = 3 then
+    8 * 2^n - 3
+  elif n = 0 then
+    thisproc( m - 1, 1 )
+  else
+    thisproc( m - 1, thisproc( m, n - 1 ) )
+  end if
+end proc: