sig
external ( + ) : int32 -> int32 -> int32 = "%int32_add"
external ( - ) : int32 -> int32 -> int32 = "%int32_sub"
external ( * ) : int32 -> int32 -> int32 = "%int32_mul"
external ( / ) : int32 -> int32 -> int32 = "%int32_div"
external ( << ) : int64 -> int -> int64 = "%int32_lsl"
external ( >> ) : int64 -> int -> int64 = "%int32_asr"
end