P. Décision, 20 1.1.1 Décision et première solution

Q. Properties, 61 2.1 Queries Definition and Basic Properties, 61 2.1.2 Class Invariance Property . 64 2.1.3 Closure Property . . . . . . . . . . . . . . . . . . 66

C. Queries and .. , 66 2.2.1 Definition, 66 2.2.2 Class Invariant: Formula Hypergraph . . . . . . 67 2.2.3 Class Properties Written with Hypergraphs, p.68

A. Properties and S. , 70 2.3.1 Existential Conjunctive Queries Minor Closure 70 2.3.2 Summary, 71 2.3.3 Queries Complexity Classes . . . . . . . . . . . . 71

C. Queries and A. , 72 3.1 Quantifier-Free Conjunctive Queries and Acyclicity . . 72 3.1.1 Acyclicity: Definition and Properties, 72 3.1.2 Consequences on Quantifier-Free Conjunctive Queries, p.76

.. The-whole-picture, 84 3.3.1 The Trivial Class, 86 3.3.3 Conjunctive Queries . . . . . . . . . . . . . . . . 88

B. Incremental-circuit, 42 3.3 Final algorithm, Decision of acyclic existential conjunctive queries . . . . . 77 4.2 Count and enumeration for acyclic QFCQ . . . . . . . . . 78

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