declare fun {Producent X}
           {Delay ({OS.rand} mod 1000)}
           if X \= 0
           then ({OS.rand} mod 100)+1 | {Producent X-1}
           else nil
           end
        end

declare fun {Przetwornik A1 A2 A3}
       {Delay ({OS.rand} mod 1000)}
       case A1
       of H|T then case A2
               of Q|W then case A3
                   of E|R then if {Abs (Q-E)} < H then
                          if H < (Q+E) then (H#Q#E)|{Przetwornik T W R}
                          else {Przetwornik T W R} end
                           else {Przetwornik T W R} end
                   [] nil then nil
                   end
               [] nil then nil
               end
       [] nil then nil
       end
    end

declare fun {Konsument L}
       {Delay ({OS.rand} mod 1000)}
       case L
       of (A#B#C)|T then local P = {IntToFloat (A+B+C)}/2. in
                {Sqrt P*(P-{IntToFloat A})*(P-{IntToFloat B})*(P-{IntToFloat C})}|{Konsument T}
                 end
       [] nil then nil
       end
    end
declare fun {Suma X Y Z}
       local P1
          thread P1 = {Konsument {Przetwornik {Producent X} {Producent Y} {Producent Z}}} end
          thread {Browse P1} end
       in
          local fun {Rek L Acc}
               case L
               of H|T then {Rek T Acc+H}
               [] nil then Acc
               end
            end
          in {Rek P1 0.0}
          end
       end
    end
{Browse {Suma 10 10 10}}

local P1 P2 P3 S1 S2 in
thread P1 = {Producent 10} end
thread {Browse P1} end
thread P2 = {Producent 10} end
thread {Browse P2} end
thread P3 = {Producent 10} end
thread {Browse P3} end
thread S1 = {Przetwornik P1 P2 P3} end
thread {Browse S1} end
thread S2 = {Konsument S1} end
thread {Browse S2} end
end