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An important goal of computational linguistics has been to use linguistic theory to guide the construction of computationally efficient real-world natural language processing systems. At first glance, generalized phrase structure grammar (GPSG) appears to be a blessing on two counts. First, the precise formalisms of GPSG might be a direct and transparent guide for parser design and implementation. Second, since GPSG has weak context-free generative power and context-free languages can be parsed in by a wide range of algorithms, GPSG parsers would appear to run in polynomial time. This widely-assumed GPSG efficient parsability result is misleading: here we prove that the universal recognition problem of current GPSG theory is exponential-polynomial time hard, and assuredly intractable. The paper pinpoints sources of complexity (e.g. metarules and the theory of syntactic features) in the current GPSG theory and concludes with some linguistically and computationally motivated restrictions on GPSG.

An important goal of computational linguistics has been to use linguistic theory to guide the construction of computationally efficient real-world natural language processing systems. At first glance, generalized phrase structure grammar (GPSG) appears to be a blessing on two counts. First, the precise formalisms of GPSG might be a direct and transparent guide for parser design and implementation. Second, since GPSG has weak context-free generative power and context-free languages can be parsed in by a wide range of algorithms, GPSG parsers would appear to run in polynomial time. This widely-assumed GPSG efficient parsability result is misleading: here we prove that the universal recognition problem of current GPSG theory is exponential-polynomial time hard, and assuredly intractable. The paper pinpoints sources of complexity (e.g. metarules and the theory of syntactic features) in the current GPSG theory and concludes with some linguistically and computationally motivated restrictions on GPSG.

A central goal of mathematical linguistics is to precisely determine the power of a linguistic theory. Traditionally, formal language theory (the Chomsky hierarchy) and its generative power analyses have translated this question into the narrower question of how unrestricted the rule format of a theory is. Modern computational complexity theory offers another, more useful, translation: how much of what computational resources does a theory consume? Complexity theory also offers a new perspective on descriptive adequacy. In a descriptively adequate linguistic theory, the structural descriptions and computational power of the theory match those of an ideal speaker-hearer. The primary goal of this paper is to demonstrate how considerations from computational complexity theory can inform grammatical theorizing. To this end, the paper revises generalized phrase structure grammar (GPSG) linguistic theory so that its computational power more closely matches the limited computational ability of an ideal speaker-hearer. A second goal is to provide a theoretical framework within which to better understand the wide range of GPSG models that have appeared in the theoretical and computational linguistics literature, embodied in formal definitions as well as in implemented computer programs.

A central goal of mathematical linguistics is to precisely determine the power of a linguistic theory. Traditionally, formal language theory (the Chomsky hierarchy) and its generative power analyses have translated this question into the narrower question of how unrestricted the rule format of a theory is. Modern computational complexity theory offers another, more useful, translation: how much of what computational resources does a theory consume? Complexity theory also offers a new perspective on descriptive adequacy. In a descriptively adequate linguistic theory, the structural descriptions and computational power of the theory match those of an ideal speaker-hearer. The primary goal of this paper is to demonstrate how considerations from computational complexity theory can inform grammatical theorizing. To this end, the paper revises generalized phrase structure grammar (GPSG) linguistic theory so that its computational power more closely matches the limited computational ability of an ideal speaker-hearer. A second goal is to provide a theoretical framework within which to better understand the wide range of GPSG models that have appeared in the theoretical and computational linguistics literature, embodied in formal definitions as well as in implemented computer programs.

Susanna Holcombe, a very sensitive and free spirited young lady, tries to fit in to society. But it is very hard for a Victorian woman to carve her own path, and she is almost forced to marry colonel Dymond. This book tells about her trials and tribulations. Can she find her place at last? Perfect for fans of Mary Elizabeth Braddon and Anthony Trollope, and those who want a Jane Austen novel with a twist. Anne Isabella Thackeray Ritchie was the eldest daughter of William Makepeace Thackeray, author of Vanity Fair. - Summary by Stav Nisser.

2Inside the Lines

By Earl Derr Biggers and Robert Welles Ritchie

As World War I commences, a plucky young American woman in Europe on a business trip begins to realize that she may have remained too long. She and others anxious to leave for home are caught up in events swirling about them. A mysterious British officer becomes involved. This romance-tinged spy thriller begins on a train in Calais bound for Paris and ends in Gibraltar. <br><br> Based on a 1915 play of the same name, the novel was adapted for the screen in a 1918 silent version and again as a “talky” in 1930. This was the third novel written by Biggers, who went on to write six Charlie Chan novels in the 1920’s and 1930’s. -- Lee Smalley

3Book of Sibyls: Mrs. Barbauld, Miss Edgeworth, Mrs. Opie, Miss Austen

By Anne Isabella Thackeray Ritchie

This book is a biography of four woman authors whose names were well known by readers at the time of its publication (1883) : Anna Barbaud, Maria Edgeworth, Amelia Opie, and Jane Austen. Though most of us today are only familiar with the writings of Austen, all four of these women are well worth taking the time to get to know. The author, Anne Thackeray Ritchie, was the eldest daughter of William Makepeace Thackeray. - Summary by Ciufi Galeazzi

4Dust of the Desert

By Robert Welles Ritchie

Roads of men thread the world. They thunder with a life flood. They are vibrant with a pulse of affairs. By land and water and air they link to-day to to-morrow. But El Camino de los Muertos (the Road of the Dead Men) is a dim highway leading nowhere but back and back to forgotten yesterdays. - Summary from the prologue