Interposition or nullification bills have been introduced in several state legislatures. Though the resolutions followed the "interposition" approach of Madison, Jefferson advocated nullification. These acts were stricken down by the courts, whether labelled acts of interposition or nullification. These resolutions are considered the foundational documents of the theories of nullification and interposition. Interposition and nullification have been raised recently in several state legislatures. In theory, nullification differs from interposition in several respects. As noted above, the courts have rejected both nullification and interposition. During the 19th century, several states attempted or threatened interposition or nullification. Though interposition and nullification are similar, there are some differences. In practice, nullification and interposition often have been confused, and sometimes have been used indistinguishably. The interposition graft provides extended stability and also structure to the area of the perforation. An interposition graft is also often used. Investigators suggest that the trapeziectomy without any interposition or reconstruction is preferred. Through Divine interposition, the poison failed to accomplish its purpose. Interposition also involves a declaration that a federal law is unconstitutional.