摘要: This article introduces a logical system, called BV, which extends multiplicative linear logic by noncommutative self-dual operator. extension is particularly challenging for the sequent calculus, and so far, it not achieved therein. It becomes very natural in new formalism, calculus of structures, main contribution this work. Structures are formulas subject to certain equational laws typical sequents. The structures obtained generalizing such way that top-down symmetry derivations observed, employs inference rules rewrite inside at any depth. These properties, addition allowing design yield modular proof cut elimination.