Mild Context-Sensitivity and Tuple-Based Generalizations of Context-Grammar

This paper classifies a family of grammar formalisms that extendcontext-free grammar by talking about tuples of terminal strings, ratherthan independently combining single terminal words into larger singlephrases. These include a number of well-known formalisms, such as headgrammar and linear context-free rewriting systems, but also a new formalism,(simple) literal movement grammar, which strictly extends the previouslyknown formalisms, while preserving polynomial time recognizability.