#!/bin/sh
i=9
k=8
while test $i -gt 4 ;  do
  j=`expr $i + 1`
  if  [ $i -gt 6 ] ;  then j=`expr $i + 100`;  fi
  echo $i -- $j
  i=`expr $i - 1`
done
KK="k1d"
KL="k1d"
KM="kd"
if [ $KK != $KL ]
 then echo yes
 else echo no
fi
if  [ $KK = $KL ]&&[ $KK != $KM ]
 then echo yes1
 else echo no1
fi
if  [ $KK = $KL ] || [ $KK != $KM ] ;then echo yes2  ;   else echo no2
fi



=========================
kondo@kondo-PC ~/shell
$ source if.sh
9 -- 109
8 -- 108
7 -- 107
6 -- 7
5 -- 6
no
yes1
yes2