 Everett (1957) also eliminated collapses, so that after a measurement object system and measuring device (or observer) end up in an entangled superposition. To reconcile this description with the uniqueness of our experience, Everett introduced the notion of relative state: individual terms of the superposition represent different definite measurement results, and relative to the corresponding device states the object systems possess definite properties as well. This interpretative move was worked out by DeWitt and others into the idea that all measurement results represented in the post-measurement superposition are realized: in a measurement worlds are multiplied, and in each world a different measurement outcome becomes determinate.