resources/sksl/runtime_errors/IllegalRecursionMutual.rts

// Expect 1 error

// Straightforward mutual recursion (not allowed)
bool is_even(int n);
bool is_odd (int n) { return n == 0 ? false : is_even(n - 1); }
bool is_even(int n) { return n == 0 ? true  : is_odd (n - 1); }