# Pastebin RYL5q6ZV Few of the methods adopted for constraint handling in literature are: 1. choose g_best depending on crowding distance, and use mutation to improve diversity. 2.penalty function, though it has disadvantage for selecting the appropriate factors. 3.By rejection of infeasible solution - but this will decrease diversity. 4. numerical gradient method, I am not sure about this. 5. convert constraint into unconstraint bi-objective- on the basis of crowding distance. 6 . In this method, both feasible and infeasible p_best are stored and updated while only converging feasible towards pareto front and using both feasible and infeasible p_best for deciding g_best. This one I like the best. or we can work on a completely new idea.