//** Below makes list of all industries and then only keeps coal mines;

local industrylist = GSIndustryList();
industrylist.Valuate(GSIndustry.GetIndustryType);
industrylist.KeepValue(5);

//** Basicly the idea is to get the highest producing industry at the top of the list. But
* it seems that it sorts the list by industry ID's. Industrylist_a = output for testing purpose
//**

industrylist.Sort(GSList.SORT_BY_VALUE, false);
local industrylist_a = industrylist.Begin();