true + null; // expect runtime error
true + true; // expect runtime error
true + "s"; // expect runtime error
true + 123; // expect runtime error

null + null; // expect runtime error
null + true; // expect runtime error
null + "s"; // expect runtime error
null + 123; // expect runtime error

123 + null; // expect runtime error
123 + true; // expect runtime error
123 + "s"; // expect runtime error

"s" + null; // expect runtime error
"s" + true; // expect runtime error
"s" + 123; // expect runtime error