The Elway Theorem was a proposal for a new method of transportation utilizing dimensional shifting. It was abandoned, however, in the mid-23rd century, when it was discovered that utilizing such transportation would result in cumulative damage to the cellular chemistry of anyone using such technology.
In 2366, upon studying a faint nuclear vibration left behind as a byproduct of a transportation method being utilized by Ansata terrorists, Wesley Crusher realized that they were using a folded-space transporter based on the Elway Theorem in order to prevent the Rutian authorities from tracking their movements. (TNG: "The High Ground")