execl("/bin/ps", "ps", "-ax", 0) 코드에서 왜 ps가 중복될까요??

ls /tmp/glibc-20080505/posix/exec*
execl.c  execle.c  execlp.c  execv.c  execve.c  execvp.c

// /tmp/glibc-20080505/posix/execlp.c
...
     30 int
     31 execlp (const char *file, const char *arg, ...)
-    32 {
|    33 #define INITIAL_ARGV_MAX 1024
...
|    67   int ret = execvp (file, (char *const *) argv);

// /tmp/glibc-20080505/posix/execvp.c
||   63       /* Don't search when it contains a slash.  */
||   64       __execve (file, argv, __environ);

// /tmp/glibc-20080505/posix/execve.c
     27 __execve (path, argv, envp)
     28      const char *path;
     43 weak_alias (__execve, execve)

// /usr/src/linux/arch/x86/kernel/syscall_table_32.S
     12         .long sys_unlink        /* 10 */
     13         .long sys_execve
     14         .long sys_chdir

// /usr/src/linux/arch/x86/kernel/process_32.c
    670 asmlinkage int sys_execve(struct pt_regs regs)
-   671 {
|   672         int error;