xev -even keyboard   cursor down:
KeyPress event, serial 24, synthetic NO, window 0x3400001,
    root 0x68, subw 0x0, time 4023036582, (95,63), root:(646,508),
    state 0x10, keycode 104 (keysym 0xff8d, KP_Enter), same_screen YES,
"   XLookupString gives 1 bytes: (0d) "
"   XmbLookupString gives 1 bytes: (0d) "
    XFilterEvent returns: False

KeyRelease event, serial 27, synthetic NO, window 0x3400001,
    root 0x68, subw 0x0, time 4023036684, (96,64), root:(647,509),
    state 0x10, keycode 104 (keysym 0xff8d, KP_Enter), same_screen YES,
"   XLookupString gives 1 bytes: (0d) "
    XFilterEvent returns: False

xev -even keyboard   cursor left:
KeyPress event, serial 24, synthetic NO, window 0x3400001,
    root 0x68, subw 0x0, time 4023141221, (63,149), root:(614,594),
    state 0x10, keycode 100 (keysym 0xff23, Henkan_Mode), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 27, synthetic NO, window 0x3400001,
    root 0x68, subw 0x0, time 4023141324, (63,149), root:(614,594),
    state 0x10, keycode 100 (keysym 0xff23, Henkan_Mode), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False

xev -even keyboard   AltGr:
KeyPress event, serial 24, synthetic NO, window 0x3400001,
    root 0x68, subw 0x0, time 4023187484, (98,128), root:(649,573),
    state 0x10, keycode 113 (keysym 0xff51, Left), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 27, synthetic NO, window 0x3400001,
    root 0x68, subw 0x0, time 4023187604, (98,128), root:(649,573),
    state 0x10, keycode 113 (keysym 0xff51, Left), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False