Tags:Boolean algebra, classical logic, computational complexity, decidability, exponential time, finitary consequence relation, Lambek Calculus, Nonassociative Lambek Calculus and substructural logic
Abstract:
The Nonassociative Lambek Calculus (NL) represents a logic devoid of the structural rules of exchange, weakening, and contraction, and it does not presume the associativity of its connectives. Its finitary consequence relation is decidable in polynomial time. However, the addition of classical connectives conjunction and disjunction (FNL) makes consequence relation undecidable. Interestingly, if these connectives are distributive, the consequence relation is decidable in exponential time. This paper provides the proof, that we can merge classical logic and NL (i.e. BFNL), and still consequence relation is decidable in exponential time.
Complexity of Nonassociative Lambek Calculus with Classical Logic