Structural rule A famous structural rule is known as cut. Considerable effort is spent by proof theorists in showing that cut rules are superfluous in various logics. More precisely, what is shown is that cut is only (in a sense) a tool for abbreviating proofs, and does not add to the theorems that can be proved. The successful 'removal' of cut rules, known as "cut elimination", is directly related to the philosophy of "computation as normalization" (see Curry–Howard correspondence); it often gives a good indication of the complexity of deciding a given logic. Structural rule In proof theory, a structural rule is
The Mirror (Ja Rule album) The Mirror (Ja Rule album) The Mirror is the first mixtape by rapper Ja Rule, originally planned to be released in 2007. Two singles, "Uh-Ohhh!" and "Body," were released in 2007 to poor chart performance. After tracks from the unreleased album were leaked online, Ja Rule decided to re-record the album, but later decided to release it as a mixtape on July 31, 2009 along with two bonus tracks, "Free" and "Style On 'Em." Prior to the start of recording for this album, Ja Rule's last original studio album was "R.U.L.E." in 2004; The Inc. released a greatest hits compilation,