Itr 7 filling

Filling ITR 7 is made most complicated which otherwise should have been most simple/ In sch.AI all income is required to fill; but other schedules which should have been populated to TTi is mis led- e-g Sch OS seems to be similar to AI , but if I fill up both the schedules I get all income taxable without considering the Application of income.. ,so fill up only AI and leave OS blank for items already filled in AI