 In turn, material fallacies may be placed into the more general category of informal fallacies.Yet, verbal fallacies may be placed in either formal or informal classifications; compare equivocation which is a word or phrase based ambiguity, e. g. "he is mad", which may refer to either him being angry or clinically insane, to the fallacy of composition which is premise and inference based ambiguity, e. g. "this must be a good basketball team because each of its members is an outstanding player".Even the definitions of the classes may not be unique.