The system allows {HEAD ~ a user} to create {TAIL ~ a semantic object data model} of the database schema 
The system allows { HEAD ~ a user } to create { TAIL ~ a semantic object data model } of the database schema
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH