Hi! I have a constraint (shown at the photo below) wherein two sets need to be subtracted. I tried introducing another set Kw with a definition of k-Ks but it says subtraction of element valued expressions require the set range to be equal, but the ranges domain set "Subblock" and set "Candidate_Subblocks" differ.
above is the current code I have. Do you have any Idea on how I can code my constraint?
Best answer by deannezhang
Making both Candidate_Subblock and Subblock_Difference as a subset of Subblock and change the definition of Subblock_Difference like below should work.
Making both Candidate_Subblock and Subblock_Difference as a subset of Subblock and change the definition of Subblock_Difference like below should work.
YL(k,t) - Binary Variable(set to 1 if subblock k executes loading activity in period t)
x(v,k) - Binary variable(1 if subblock K is reserved for vessel V)
Tv - subset of period/s when vessel v loads or unloads containers
constraint 7: denotes whether a subblock performs a loading/unloading activity
If Tv is input, which means it does not change depending on variables, what you can do is to introduce parameter As Tv. For example, Valid_v_t(v,t) is 1 if vessel v can load/unload at time t. then (7) can be something like
