Bibi-binary express any number, it suffices to enumerate the (hexadecimal) digits that make it up. For example: the number written as "2000" in base ten, which translates to "7D0" in conventionally-written hexadecimal, would in Bibi-binary be spoken aloud as "BIDAHO". Contrary to the numeric conventions used in modern computers, the bibi-binary system represents negative numbers using one's complement, rather than two's complement. Thus: and their sum is written as "1 1111" (one of two representations of zero in this system; zero can also be written as "0 0000"). On modern machines, in classic binary notation, −7 would be written 1 1001,
Contact binary (small Solar System body) are expected to be contact binaries with two lobes in mutual contact. Contact binary (small Solar System body) A contact binary is a small Solar System body that is composed of two bodies that have gravitated toward each other until they touch. This means contact binaries have odd shapes. Comet Churyumov–Gerasimenko and Comet Tuttle are most likely contact binaries. Asteroids suspected of being contact binaries include the unusually elongated 624 Hektor and the bilobated 216 Kleopatra and 4769 Castalia. 25143 Itokawa, which was photographed by the "Hayabusa" probe, also appears to be a contact binary which has resulted in an