11. A method for operating a speech recognition system as recited in claim 10 , wherein the node and link structure of the set of phrases includes a single node or multiple nodes connected by a directional link that indicates a progression of the nodes of a particular one of the set of phrases.
10. A method for operating a speech recognition system as recited in claim 1 , further comprising: optimizing the grammar definition layer by, defining a set of phrases corresponding to the combinations of word groups the speech recognition system is meant to recognize, defining each of the set of phrases in a node and link structure, wherein a given node is defined by one or more words, and wherein a given link connects the one or more words of one node to the one or more words of another node, identifying redundant nodes by examining the node and link structures of each of the set of phrases so as to generate and substitute a single node for the redundant nodes, wherein redundant nodes are defined by identical words, and wherein each of the redundant nodes has a respective outgoing link to a same successor node, examining the node and link structures to identify nodes that are capable of being vertically grouped and grouping the identified nodes to define vertical word groups, and fusing horizontally linked nodes of the set of phrases that are not vertically grouped and that represent a single sentence path into fused word groups, wherein the vertical word groups and the fused word groups are linked to define an optimized grammar structure.