1. A system for identifying at least one herbal ingredient effective in treating an illness classified under TCM (Traditional Chinese Medicine) comprising: one or more computer readable storage media; program instructions for a relevance index program module stored on the one or more computer readable storage media that, when executed by a processor, direct the processor to: construct TCM illness entity artificial neural networks from a plurality of TCM illness entities, wherein each TCM illness entity artificial neural network identifies a single TCM illness entity, wherein each TCM illness entity artificial neural network computes a relevance index indicating a probability of intersection between the single TCM illness entity and a selected one or more TCM herbal ingredient entities; construct TCM herbal ingredient entity artificial neural networks from a plurality of TCM herbal ingredient entities, wherein each TCM herbal ingredient entity artificial neural network identifies a single TCM herbal ingredient entity, wherein each TCM herbal ingredient entity artificial neural network computes a relevance index indicating a probability of intersection between the single TCM herbal ingredient entity and a selected one or more TCM illness entities; train the TCM illness entity artificial neural networks and the TCM herbal ingredient entity artificial neural networks from a first training dataset, comprising the plurality of TCM illness entities and one or more illness-associated-symptoms for each TCM illness entity of the plurality of TCM illness entities, and a second training dataset, comprising the plurality of TCM herbal ingredient entities and one or more ingredient-effective-symptoms for each TCM herbal ingredient entity of the plurality of TCM herbal ingredient entities; in response to receiving an indication of a referential entity selected from the plurality of TCM illness entities: computing relevance indexes for the referential entity using the TCM herbal ingredient entity artificial neural networks; and identifying at least one effective TCM herbal ingredient entity from the relevance indexes.