We cannot apply the fundamental rule to a chart that contains no edges. There needs to be at least one active edge and one inactive edge for anything to happen. The task of ensuring that there are some inactive edges to be found is the job of initialization. Ignoring morphology for the moment, it is quick and easy to look up words in the lexicon and find what categories they belong to. The results of such a dictionary look-up can be placed in the chart directly as inactive edges, right at the start without the need for any phrase-level parsing. So, for example, given the string 'they see her report on the nurses', we can use the lexicon included in Grammar5 to immediately build the chart shown in Figure 6.13. In doing so, we have initialized the chart. Notice that some pairs of adjacent vertices are connected by more than one edge, which is due to the category ambiguity exhibited by several of the words in the example string.
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