How to write a back substitution function given the pseudo code?

I have the pseudo code but am not sure how to convert it into an actual function of back substution

1: for i from n to 2

2: if ith row is a zero row

3: continue

4: end

5: c_nz <- column index of nonzero element of ith row

6: % divide ith row by U(i, c_nz) if you didn’t do it in fwd elimination

7: for j from i-1 to 1

8: % Eliminate c_nz column of jth row by multiplying and subtracting ith row

9: end

10: end