Each symptom is represented by {TAIL ~ a separate card} which can be independently illuminated to indicate {HEAD ~ the existence} of that symptom 
Each symptom is represented by { TAIL ~ a separate card } which can be independently illuminated to indicate { HEAD ~ the existence } of that symptom
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH