(IEEE 754) "IEEE Standard for Binary Floating-Point ArIThmetic (ANSI/IEEE Std 754-1985)" or IEC 559: "Binary floating-point arIThmetic for microprocessor systems". A standard, used by many CPUs and FPUs, which defines formats for representing floating-point numbers representations of special values (e.g. infinITy, very small values, NaN) five exceptions, when they occur, and what happens when they do occur four rounding modes and a set of floating-point operations that will work identically on any conforming system. IEEE 754 specifies formats for representing floating-point values: single-precision (32-bIT) is required, double-precision (64-bIT) is optional. The standard also mentions that some implementations may include single-extended precision (80-bIT) and double-extended precision (128-bIT) formats. [On-line document?] (2003-06-17)