It is notoriously possible for the author of a fictitious narrative to become, after a time, unable to distinguish it from a statement of actual facts. There is a case on record in which a learned judge communicated to the Psychical Society in perfect good faith a ghost story, all the principal features of which were proved to be imaginary. They had their origin in his own talent as a distinguished raconteur.

The clauses ¬p∨q, ¬p∨¬q∨r, and ¬p∨¬q∨¬r∨s are examples of definite clauses. At least in classical logic these would be equivalent to the formulae p→q, (p∧q)→r, and (p∧q∧r)→s, respectively.

to suspect the truth of a story

He is the Terror of all the Deer and Poultry-Stealers in the Neighbourhood, and is ſo implacable a Perſecutor of Pochers, that he keeps a Regiſter of all the Dogs and Guns in the Hundred, and is the Scare-Beggar of the Pariſh.