traded at umpire program 30 elf program 13 will take the first price offered by umpire program 30 and until its order it matched will take the next two prices offered by umpire program 30 then pause and wait for new instructions from computer 23 this is a u201c hurry and sell u201d strategy elf program 13 will never book any of its shares the price improvement strategy of elf program 13 is do not improve the price fig4 is a diagram depicting how fig4 a and 4b are to be read together fig4 a and 4b are henceforth referred to as fig4 at time 300 the book is as shown in fig4 let it be assumed that the previous match was a match at a price of 17 at time 302 elf program 10 establishes communication with umpire program 30 at time 304 elf program 10 registers with umpire program 30 as a buyer at time 306 elf program 10 requests a price quote umpire program 30 determines that its last match price 17 is different than the sell price of the book 18 then determines that no one else is in the crowd so at time 308 umpire.