 For the coordination problem within P to be solved by using L, all members of P must be in a position to determine the meaning of all the sentences of L. In other words, it must be that members of P have a way to identify the function that, for any given sentence, will deliver the corresponding meaning. Given the limitations of speakers, both physical and cognitive, there must be a finite and simple way to do this. The compositionality of L can help explain how this is possible (see entry on  compositionality). Roughly put, for L to be compositional is for the meaning of all complex expressions e1…en of L to be fully determined by the meaning of their parts and by the way such parts are composed. Thus, the functions that map sentences into their meanings will take into account the meaning of their parts and the way they are combined.