Initial data commit

Task/Mutual-recursion/S-lang/mutual-recursion.slang

@@ -0,0 +1,22 @@
+% Forward definitions: [also deletes any existing definition]
+define f();
+define m();
+
+define f(n) {
+  if (n == 0) return 1;
+  else if (n < 0) error("oops");
+  return n - m(f(n - 1));
+}
+
+define m(n) {
+  if (n == 0) return 0;
+  else if (n < 0) error("oops");
+  return n - f(m(n - 1));
+}
+
+foreach $1 ([0:19])
+  () = printf("%d  ", f($1));
+() = printf("\n");
+foreach $1 ([0:19])
+  () = printf("%d  ", m($1));
+() = printf("\n");