(* The Equilbrium Price and Quantity for a Supplied Set of Values or Costs *)



counter[v_, c_] := Reverse[Sort[Flatten[v]]] - Sort[Flatten[c]]



eq[{{1, 0}, {4, 0}, {7, 0}, {8, 8}}, {{2, 10}, {4, 10}, {4, 10}, {5, 10}}]

eq[{{1, 0}, {4, 0}, {4, 0}, {8, 8}}, {{2, 10}, {4, 10}, {4, 10}, {5, 10}}]



demandsupply[{{1, 0}, {4, 0}, {4, 0}, {8, 8}}, {{2, 10}, {4, 10}, {4, 10}, {5, 10}}]



buyerinterval[v_, c_] :=

    {Reverse[Sort[Flatten[v]]]

        [[Length[Select[counter[v, c], Positive]]]],

      Reverse[Sort[Flatten[v]]]

        [[Length[Select[counter[v, c], greaterthan[0]]] + 1]]};

greaterthan[x_] := Function[z, z >= x]

buyerinterval[{{1, 0}, {4, 0}, {4, 0}, {8, 8}}, {{2, 10}, {4, 10}, {4, 

      10}, {5, 10}}]



sellerinterval[v_, c_] :=

    {Sort[Flatten[c]]

        [[Length[Select[counter[v, c], Positive]]]],

      Sort[Flatten[c]]

        [[Length[Select[counter[v, c], greaterthan[0]]] + 1]]};

sellerinterval[{{1, 0}, {4, 0}, {4, 0}, {8, 8}}, {{2, 10}, {4, 10}, {4, 

      10}, {5, 10}}]



ep[{{1, 0}, {4, 0}, {4, 0}, {8, 8}}, {{2, 10}, {4, 10}, {4, 10}, {5, 10}}]



surplus[{{1, 0}, {4, 0}, {4, 0}, {8, 0}}, {{2, 10}, {4, 10}, {4, 10}, {5, 10}}]

surplus[{{1, 0}, {4, 0}, {4, 0}, {8, 8}}, {{2, 10}, {4, 10}, {4, 10}, {5, 10}}]