Let S={a,b,c,d,e} and let T be the set of all ten 2-element subsets of S. Show that there exists no injective function f:S→{0,1,2,...,|T|} such that the function g: T→ {1,2,...,|T|} defined by g({i,j})=|f(i)-f(j)|is bijective.
Let S={a,b,c,d,e} and let T be the set of all ten 2-element subsets of S. Show that there exists no injective function f:S→{0,1,2,...,|T|} such that the function g: T→ {1,2,...,|T|} defined by g({i,j})=|f(i)-f(j)|is bijective.
This equivalent to asking “Is it possible to select five different elements from so that no two pairs have the same difference?”