Data commit

Task/Mutual-recursion/ALGOL-W/mutual-recursion.alg

@@ -0,0 +1,18 @@
+begin
+    % define mutually recursive funtions F and M that compute the elements   %
+    % of the Hofstadter Female and Male sequences                            %
+
+    integer procedure F ( integer value n ) ;
+        if n = 0 then 1 else n - M( F( n - 1 ) );
+
+    integer procedure M ( integer value n ) ;
+        if n = 0 then 0 else n - F( M( n - 1 ) );
+
+    % print the first few elements of the sequences                          %
+    i_w := 2; s_w := 1; % set I/O formatting                                 %
+    write( "F: " );
+    for i := 0 until 20 do writeon( F( i ) );
+    write( "M: " );
+    for i := 0 until 20 do writeon( M( i ) );
+
+end.