The thrust of this book is to provide a model of lexical relations which reconciles the lexicon's idiosyncratic and productive aspects. Building on work in Head-driven Phrase-Structure Grammar, an organization of lexical knowledge is proposed--- called the Type Underspecified Hierarchical Lexicon--- through which partial regularities, medium-size generalization, and truly productive processes receive a unified model. Its basic thesis is that all lexical relations reduce to categorization (the membership of the two related lexemes in a common category) and that category intersection is the only mechanism needed to model lexical processes provided lexical items can be stored partially underspecified as to their category membership. Aside from the conceptual simplification that results from this move, the book demonstrates that several empirical and theoretical benefits accrue to this architecture; in particular, many salient properties of morphological processes are shown to reduce to inherent, formal properties of the organization of the lexicon.

• Contents 
• 1 
• Introduction
• 1.1 
• Lexical Knowledge
• 1.2 
• Sign-based, category-based grammars
• 1.3 
• The psychological reality of grammars
• 2 
• Two kinds of lexical relations
• 2.1 
• Classificatory Relations in a Hierarchical Lexicon
• 2.1.1 
• The Hierarchical Lexicon
• 2.1.2 
• The formalism
• 2.2 
• Morphological relations
• 2.2.1 
• Morphological relations in Type Hierarchies
• 2.2.2 
• Why on-line application of lexical rules is not the optimal solution
• 2.3 
• Summary
• 3 
• On-line Type Construction
• 3.1 
• Two kinds of lexical productivity
• 3.2 
• How on-line typing works
• 3.3 
• Morphological relations within a TUHL
• 3.4 
• The benefits of on-line type construction
• 3.4.1 
• Categorial productivity
• 3.4.2 
• Intensionally vs. extensionally defined word classes: the problem of exceptions
• 3.4.3 
• AND/OR nets and conjunctive vs. disjunctive application of rules
• 3.5 
• Summary
• 4 
• A typed constituent structure-based morphology
• 4.1 
• A typed constituent-structure morphology
• 4.1.1 
• Why we need a constituent structure
• 4.1.2 
• The lexeme hierarchy
• 4.2 
• Morphological blocking
• 4.2.1 
• The obligatoriness of inflection
• 4.2.2 
• Irregular past tenses
• 4.2.3 
• Subregularities
• 4.3 
• Summary
• 5 
• The AND/OR nature of morphological processes
• 5.1 
• Stem selection and disjunctive vs. conjunctive rule application
• 5.1.1 
• Suppletive stems and morpholexical rules
• 5.2 
• Latin verbal morphology
• 5.3 
• Subregularities in derivational morphology
• 5.4 
• Headed words and other mice-eater problems
• 5.5 
• Comparison with other approaches to morphology
• 5.5.1 
• Are affixes heads of morphological structures?
• 5.5.2 
• Morpheme vs. construction-based constituent-structure morphology
• 5.5.3 
• Recent approaches to morphology within HPSG
• 5.6 
• Summary
• 6 
• Conclusion
• A 
• Type declarations
• A.1 
• HPSG II type declarations
• A.2 
• New or revised types
• A.3 
• Some HPSG principles
• A.4 
• Abbreviations
• Bibliography
• Name Index
• Subject Index