Function with illegal identifier can be defined, but can't be unset.

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/local/share/locale' -DPACKAGE='bash' 
-DSHELL -DHAVE_CONFIG_H  -I.  -I. -I./include -I./lib   -O4 -march=i686
uname output: Linux node1 2.6.7 #6 SMP Sun Aug 22 23:49:58 EDT 2004 i686 
unknown unknown GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 3.0
Patch Level: 0

Description:

    Function with illegal identifier (eg. with hyphen or dot) can be
    defined, as in
        func-aa () { echo 11; }
        func.aa () { echo 22; }
    But, they cannot be removed, as in
        unset func-aa func.aa           --> ...: not a valid identifier