This header file provides function prototypes for the math functions conventionally found in libm, the standard C math library. Although these functions are not part of the minimal C library, an implementation of the math functions is available in the FreeBSD math library; see Chapter 14 for details. This header file also defines various floating-point constants, such as the value of , as described in the Unix CAE specification. Since these functions and their implementations are fully standard, they are not described in further detail here; refer to the ISO C and Unix standards for more information.