set -x output of test operator is irretating

[Toralf Förster]

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: i686-pc-linux-gnu-gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib   -O2 -march=pentium-m 
-fomit-frame-pointer -pipe
uname output: Linux n22 2.6.25-gentoo-r7 #6 Thu Jul 24 21:39:48 CEST 2008 i686 
Intel(R) Pentium(R) M processor 1700MHz GenuineIntel GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 3.2
Patch Level: 33
Release Status: release

Description:
        I'm wondering why in the example (see below) the right side is prefixed 
with a '\' wheras the left side is unchanged.

Repeat-By:
        tfoerste@n22 ~ $ echo "1 2 3 4" | while read a b c d; do [[ "$a" = "$b" 
|| "$a" = "$c" || "$a" = "$d" ]] && echo oops; done
        + read a b c d
        + echo '1 2 3 4'
        + [[ 1 = \2 ]]
        + [[ 1 = \3 ]]
        + [[ 1 = \4 ]]
        + read a b c d
        ++ echo -ne '\033]0;tfoerste@n22:~\007'

-- 
MfG/Sincerely

Toralf Förster
pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3

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