unknown_cf_rule1a(nt1,prep,s).
unknown_cf_rule1a(nt1,noun,s).
unknown_cf_rule1a(s,det,np).
unknown_cf_rule1a(np,noun,np).
unknown_cf_rule1a(np,adj,np).
unknown_cf_rule1a(np,det,np).
unknown_cf_rule1a(np,verb,nt1).
unknown_cf_rule1a(nt1,noun,nt1).
unknown_cf_rule1a(nt1,adj,nt1).
unknown_cf_rule1a(nt1,det,nt1).
unknown_cf_rule0(s).