$ if (("$n1" < "$n2")); then echo "number $n1 is smaller with the difference of 12 from $n2" ; else echo "$n2 is larger than $n1" ; fi
number 23 is smaller with the difference of 12 from 35
$ n1=$n2 ; n2=$n1
$ if (("$n1" < "$n2")); then echo "number $n1 is smaller with the difference of 12 from $n2" ; else echo "$n2 is larger than $n1" ; fi
[b]35 is larger than 35