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,
Binary logarithm and ISO 80000-2), and (with a prior statement that the default base is 2) . Historically, the first application of binary logarithms was in music theory, by Leonhard Euler: the binary logarithm of a frequency ratio of two musical tones gives the number of octaves by which the tones differ. Binary logarithms can be used to calculate the length of the representation of a number in the binary numeral system, or the number of bits needed to encode a message in information theory. In computer science, they count the number of steps needed for binary search and related algorithms. Other