MATLAB showing error : undefined variable

So I was just solving a system of linear inequations using simple for loops and if statements as shown in the image. But upon running an error pops up, saying that one of the variable is undefined. I could not bring myself to solve the issue because I do not understand why is it saying so. All looks good to me. Please help.

Answer 1

[Image Analyst]

Line 22 assumes that cz got assigned. But if you look at line 7 you'll see that the criteria is never met and so line 8 never gets executed and so cz is not assigned a value before it comes time to use it in line 22. Why is that criteria not met? Tha's for you to figure out.