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
3-Minute Rule 3-Minute Rule "3-Minute Rule" is the 7th track on the album "Paul's Boutique" by American hip hop group the Beastie Boys, released on July 25, 1989. The track was produced and written by the Beastie Boys & the Dust Brothers, and engineered by Mario Caldato & Allen Abrahamson. Despite its title, the song is actually 3 minutes 39 seconds. It begins with the sound of what is apparently a ping-pong ball being hit back and forth. Then Mike D raps from about the 0:12 mark to around the 1:12 mark. MCA follows from about 1:14 to 2:00. Finally, Ad-Rock takes