In the law of evidence, a presumption of a particular fact can be made without the aid of proof in some situations. The types of presumption include a rebuttable discretionary presumption, a rebuttable mandatory presumption, and an irrebuttable or conclusive presumption. The invocation of a presumption shifts the burden of proof from one party to the opposing party in a court trial. Presumptions are sometimes categorized into two types: presumptions without basic facts, and presumptions with basic facts. In the United States, mandatory presumptions are impermissible in criminal cases, but permissible presumptions are allowed.The ancient Jewish law code, the Talmud, included reasoning from presumptions (hazakah), propositions taken to be true unless there was reason to believe otherwise, such as "One does not ordinarily pay a debt before term." The same concept was found in ancient Roman law, where, for example, if there was doubt as to whether a child was really the issue of someone who had left money in a will, the presumption was in favour of the child. Medieval Roman and canon law graded presumptions according to strength: light, medium or probable, and violent. These gradings and many individual presumptions were taken over into English law in the seventeenth century by Edward Coke.There are two types of presumption: rebuttable presumption and conclusive presumption. An example of presumption without basic facts is presumption of innocence.An example of presumption with basic facts is Declared death in absentia, e.g., the law says if a person has been missing for seven years or more (basic fact), that person is presumed dead.[citation needed]