Русско-англо-русский юридический словарь

A conclusive presumption (in Latin, praesumptio iuris et de iure), also known as an irrebuttable presumption, is a type of presumption used in several legal systems. In English law, a conclusive presumption is a presumption of law that cannot be rebutted by evidence and must be taken to be the case whatever the evidence to the contrary. (Wikipedia)

Conclusive Presumption or absolute presumption or irrebuttable presumption of law refers to presumption which cannot be overcome or changed by any additional evidence or argument. It refers to rules of law and are usually mere fictions. Modern courts repudiate conclusive presumptions when they are not fictions. For example, a child below 7 years of age is incapable of committing a felony. (USLegal)