| isalnum() | isalpha() | iscntrl() | isdigit() | isgraph() |
| islower() | isprint() | ispunct() | isspace() | isupper() |
| isxdigit() | tolower() | toupper() |
| acos() | asin() | acosh() | asinh() | atan() |
| atanh() | sin() | cos() | tan() | sinh() |
| cosh() | atan2() | exp() | fabs() | ceil() |
| floor() | sqrt() | log() | log10() | pow() |
| fclose() | clearerr() | feof() | ferror() | fflush() |
| fopen() | printf() | scanf() | getc() | putc() |
| fread() | fwrite() |
