(b) (c) (d) alters a document without authority in such a manner that if the alteration had been authorised it would have altered the effect of the document; introduces into a document without authority while it is being drawn up matter which if it had been authorised would have altered the effect of the document; signs a document— (i) in the name of any person without his or her authority whether such name is or is not the same as that of the person signing; (ii) in the name of any fictitious person alleged to exist, whether the fictitious person is or is not alleged to be of the same name as the person signing; (iii) in the name represented as being the name of a different person from that of the person signing it and intended to be mistaken for the name of that person; (iv) in the name of a person personated by the person signing the document, if the effect of the instrument depends upon the identity between the person signing the document and the person whom he or she professes to be. 346. Intent to defraud. An intent to defraud is presumed to exist if it appears that at the time when the false document was made there was in existence a specific person, ascertained or unascertained, capable of being defrauded by it, and this presumption is not rebutted by proof that the offender took or intended to take measures to prevent such person from being defrauded in fact, nor by the fact that he or she had, or thought he or she had, a right to the thing to be obtained by the false document. CHAPTER XXXIV—PUNISHMENT FOR FORGERY. 347. General punishment for forgery. Any person who forges any document commits an offence which, unless otherwise stated, is a felony and is liable, unless owing to the circumstances of the forgery or the nature of the thing forged some other punishment is provided, to imprisonment for three years.