13. The index generator of claim 12, wherein the metagrammar includes a first section for analyzing type 1 variants and a second section for analyzing type 2 variants.
13. The index generator of claim 12, wherein the metagrammar includes a first section for analyzing type 1 variants and a second section for analyzing type 2 variants. 14. The index generator of claim 13, wherein the first section analyzes syntactic variations between original terms and variants.