premise: Using L 's work , while their system is generally easy to use , one must turn to page xxii to find a pronunciation guide , while W lists such a guide on every right-hand page . 
hypothesis: W follows the ( useful ) practice of listing a shortened pronunciation key on each right-hand page ; L 's failure to do so is a disadvantage , notwithstanding the simplicity of their system , for the user must ferret about to find the description given on page xxii to clarify any question .