usr/include/sys.s

        .set    exit,1
        .set    fork,2
        .set    read,3
        .set    write,4
        .set    open,5
        .set    close,6
        .set    wait,7
        .set    creat,8
        .set    link,9
        .set    unlink,10
        .set    exec,11
        .set    chdir,12
        .set    time,13
        .set    mknod,14
        .set    chmod,15
        .set    chown,16
        .set    break,17
        .set    stat,18
        .set    lseek,19
        .set    getpid,20
        .set    mount,21
        .set    umount,22
        .set    setuid,23
        .set    getuid,24
        .set    stime,25
        .set    ptrace,26
        .set    alarm,27
        .set    fstat,28
        .set    pause,29
        .set    utime,30
        .set    smdate,30
        .set    stty,31
        .set    gtty,32
        .set    access,33
        .set    nice,34
        .set    sleep,35
        .set    sync,36
        .set    kill,37
        .set    switch,38
        .set    setpgrp,39
        .set    dup,41
        .set    pipe,42
        .set    times,43
        .set    prof,44
        .set    setgid,46
        .set    getgid,47
        .set    signal,48
#       USG 49
#       USG 50
        .set    acct,51
        .set    setphys,52
        .set    syslock,53
        .set    ioctl,54
        .set    reboot,55
        .set    mpx,56
#       USG 57
#       USG 58
        .set    setinf,59
        .set    umask,60