Mutual recursion: Difference between revisions

=={{header|XPL0}}==

<lang XPL0>code ChOut=8, CrLf=9, IntOut=11;

ffunc M; \forward-referenced function declaration

func F(N);

int N;

return if N=0 then 1 else N - M(F(N-1));

func M(N);

int N;

return if N=0 then 0 else N - F(M(N-1));

int I;

[for I:= 0 to 19 do [IntOut(0, F(I)); ChOut(0, ^ )];

CrLf(0);

for I:= 0 to 19 do [IntOut(0, M(I)); ChOut(0, ^ )];

CrLf(0);

]</lang>

Output:

<pre>

1 1 2 2 3 3 4 5 5 6 6 7 8 8 9 9 10 11 11 12

0 0 1 2 2 3 4 4 5 6 6 7 7 8 9 9 10 11 11 12

</pre>