Bash - Gaussian Elimination Op count example

#!/bin/sh

if [[ $# -ne 2 ]]
then
 exit
fi

echo " m $1 by n $2 matrix"

n=$2
m=$1
mult=0
add=0
c=0

for ((i=1;i < m;i++))
do
 echo "row = i = $i"
 for ((j=i;j < m;j++))
 do
  ((mult=mult + (n-i+1)))
  ((add=add + (n-i+1)))
 done
 ((c=c+(m-i)*(n-i+1)))
done
echo "additions = $add"
echo "mults = $mult"
echo "summation = $c"