The essence of the legal presumption is that, by using evidence to inform specific facts within a case, a court can then ‘presume’ that the facts are true. These facts may then be used within the context of applicable laws, logic or individual rights to build a case. A legal presumption, using common evidence and facts, will stand true in court until it is disproven by a preponderance of evidence that shows otherwise. Legal presumptions apply to all sorts of legal situations, with examples including presumption of sanity (a person is presumed sane and fit for trial unless otherwise proven), presumption of constitutionality (that federal, state and local laws are drafted in accordance with the U.S. Constitution), and presumption of mailing (that a properly addressed letter given to the postal service was delivered to the addressee). In the United States of America, one of the most common legal presumptions that we’re all familiar with is that, in a court of law, an accused person is presumed to be innocent until proven guilty. In such an instance, the legal presumption is challenged by the prosecution, who attempts to deliver new evidence and reasoning that demonstrates that the legal presumption of innocence does not hold, and that the defendant is guilty. Just as well, the legal presumption is also used in lemon law to make determinations about what constitutes a lemon, and this, in turn, can inform how a lemon law court proceeding will continue.