suppose that G ~ G bar and that n = |V(G)| = 4k + 1 for k>1. (where G bar is the complement of G)

suppose thta the degree sequence of G is d1>d2>d3>...dn

a) prove that di +dn-i+1 = n-1 for each i= 1,2,3...n

b) use above to prove that G has at least one vertiex with degree (n-1)/2

all the degrees have that as a subscript after them, im just new to the forum so dont really knowhow to make it look mathematically correct. thanks heaps for any help.