isgreater(3) Library Functions Manual isgreater(3) isgreater, isgreaterequal, isless, islessequal, islessgreater, isunordered - NaN (libm -lm) #include int isgreater(x, y); int isgreaterequal(x, y); int isless(x, y); int islessequal(x, y); int islessgreater(x, y); int isunordered(x, y); glibc ( feature_test_macros(7)): : _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L ( < " ") NaN. . C99 . . (: ). isgreater() (x) > (y) x y NaN. isgreaterequal() (x) >= (y) x y NaN. isless() (x) < (y) x y NaN. islessequal() (x) <= (y) x y NaN. islessgreater() (x) < (y) || (x) > (y) x y NaN. x != y x y NaN. isunordered() NaN. isunordered() 0 NaN. isunordered() 1 x y NaN 0 . . attributes(7). +------------+------------------------------------+--------------------+ || | | +------------+------------------------------------+--------------------+ |isgreater(),| | MT-Safe | |isgreaterequal(),| | | |isless(), | | | |islessequal(),| | | |islessgreater(),| | | |isunordered()| | | +------------+------------------------------------+--------------------+ . . NaN . C11, POSIX.1-2008. POSIX.1-2001 C99. fpclassify(3) isnan(3) 3 . . : . 6.18 8 2026 isgreater(3)