Why is this? Because if alpha i beta j is equal to alpha i prime beta j prime what we have is; so, what we have is, so if alpha i beta j is equal to alpha i prime beta j prime we rewrite this as alpha i beta j minus alpha i prime beta j prime, ok.
क्योंकि यदि αi βj बराबर है αi ' βj ' तो हमारे पास क्या है ?