To monitor enrollments each semester, I have a spreadsheet that contains a list of courses with names, enrollments, and capacities. I read the spreadsheet data into a Racket list that looks like this:

$\text{'}(("$Dept$"$ "Number" "Section" "Class Nbr$"$ "Capacity" "Enrolled"$)$

$("$CS$""1000""1""11546""30""30")$

$("$CS$""1025""1""11547""30""30")$

$("$CS$""1120""1""11557""30""15")$

$("$CS$""1130""1""11548""30""18")$

$...)$

The first item in the list is the header row in the spreadsheet. It is not part of the data.

The dean and provost frequently ask me for various summary data, such as total enrollments or remaining capacity.

Write a Racket function named min$-$open$-$seats that takes such as a list as its only argument. It returns the minimum number of open seats available in any section. For example:

$>($define example $\text{'}(...))$ ; the data shown above

$>($min$-$open$-$seats example$)$

$0$

CS $1025$ has $30-30=0$ open seats. The other classes have $0,15,$ and $12$ open seats respectively.

I have provided a check$-$equal? expression for this example. Write at least two more check$-$equal? expressions to test your solution.