:: deftheorem defines FreeGenSetNSG FREEALG:def 13 :
for f being non empty FinSequence of NAT
for D being non empty disjoint_with_NAT set holds FreeGenSetNSG (f,D) = { (root-tree s) where s is Symbol of (DTConUA (f,D)) : s in Terminals (DTConUA (f,D)) } ;