A tractable extension of Linear Indexed Grammars
Bill Keller, David James Weir · 1995
Vijay-Shanker and Weir (1993) show that Linear Indexed Grammars (LIG) can be processed in polynomial time by exploiting constraints which make possible the extensive use of structure-sharing. This paper describes a formalism that is more powerful than LIG, but which can also be processed in polynomial time using similar techniques. The formalism, which we refer to as Partially Linear PATR (PLPATR) manipulates feature structures rather than stacks.