8. A computer apparatus for performing morphological analysis of natural language sentences, comprising: a word dictionary that stores words of a natural language sentence; a grammar dictionary that stores concatenation rules of words stored in said word dictionary; an analyzing processor for performing morphological analysis using said word dictionary and said grammar dictionary; and a preprocessor configured to transform concatenation rules stored in said grammar dictionary to new concatenation rules by integrating first concatenation rules representing non-null transitions and second concatenation rules representing null transitions, destinations of which are transition sources of the first concatenation rules, prior to processing by said analyzing processor, wherein said analyzing processor is configured to create an automaton corresponding to the natural language sentence based on words retrieved from said word dictionary and concatenation rules retrieved from said grammar dictionary, and generate, responsive to an input word entered into the automaton, states necessary for transition according to the concatenation rules corresponding to the input word without generating any state that is transited by pursuing a null transition succeeding the generated states.
8. A computer apparatus for performing morphological analysis of natural language sentences, comprising: a word dictionary that stores words of a natural language sentence; a grammar dictionary that stores concatenation rules of words stored in said word dictionary; an analyzing processor for performing morphological analysis using said word dictionary and said grammar dictionary; and a preprocessor configured to transform concatenation rules stored in said grammar dictionary to new concatenation rules by integrating first concatenation rules representing non-null transitions and second concatenation rules representing null transitions, destinations of which are transition sources of the first concatenation rules, prior to processing by said analyzing processor, wherein said analyzing processor is configured to create an automaton corresponding to the natural language sentence based on words retrieved from said word dictionary and concatenation rules retrieved from said grammar dictionary, and generate, responsive to an input word entered into the automaton, states necessary for transition according to the concatenation rules corresponding to the input word without generating any state that is transited by pursuing a null transition succeeding the generated states. 9. The apparatus according to claim 8 , wherein said preprocessor is further configured to transform the concatenation rules to new concatenation rules by integrating a plurality of concatenation rules representing transitions with states of null transition and capable of being consecutive.