for X being non empty set
for f1, f2, f3 being non empty homogeneous PartFunc of (X *),X st arity f1 = 0 & arity f2 = 1 & arity f3 = 2 holds
for S being non empty UAStr st the carrier of S = X & <*f1,f2,f3*> c= the charact of S holds
S is Group-like