Table of contents : Preface Organization Contents Introduction to Probabilistic Ontologies 1 Introduction 2 Ontologies 3 Uncertainty 3.1 Basics of Probability Theory 3.2 Conditional Probabilities 3.3 Boolean Random Variables and Joint Distributions 3.4 Bayesian Networks 4 Probabilistic Ontologies 5 The Five Golden Rules 5.1 Use Probabilities 5.2 Use the Right Probabilities 5.3 To Count or Not to Count 5.4 Understand the Numbers 5.5 Be Careful with Independence 6 A Specific Language 7 Conclusions References On the Complexity of Learning Description Logic Ontologies 1 Introduction 2 Description Logic 3 The Complexity of Learning 3.1 Model of Computation 3.2 Learning Frameworks and Queries 3.3 Learnability and Complexity Classes 4 Learning DL Ontologies 4.1 An Example 4.2 Complexity Results 5 Related Work 6 Conclusion References Explanation via Machine Arguing 1 Introduction 2 Background: Argumentation 3 Building Explainable Systems with Argumentative Foundations 3.1 Preprocessing 3.2 Extracting QBAFs 3.3 Explanations 3.4 Exercise 3.5 Solution 4 Extracting Argumentative Explanations from Existing AI Systems 4.1 Preprocessing 4.2 Extracting TFs 4.3 Explanations 4.4 Explanation Customisation 4.5 Feedback 4.6 Exercise 5 Conclusions References Stream Reasoning: From Theory to Practice 1 Introduction 2 Preliminaries 2.1 Continuous Queries 2.2 Resource Description Framework 2.3 SPARQL 3 Streaming Linked Data Life-Cycle 4 Processing 4.1 RSP-QL Primer 4.2 Putting RSP-QL into Practice 5 Exercise - Linear Pizza Oven 6 Conclusion References Temporal Ontology-Mediated Queries and First-Order Rewritability: A Short Course 1 Introduction 2 One-Dimensional Temporal OBDA 3 Ontology-Mediated Queries with LTL-Ontologies 4 OBDA with Temporalised DL-Lite 5 Ontology-Mediated Queries with MTL Ontologies 6 Future Research References An Introduction to Answer Set Programming and Some of Its Extensions 1 Introduction 2 History of ASP from a Logic Programming Perspective 3 ASP Language 3.1 Core ASP 3.2 Semantic Characterizations 3.3 Language Extensions 4 Semantics of Aggregates and Generalized Atoms 5 Knowledge Representation and Reasoning in ASP 6 Implementations and Applications 6.1 System algorithms 6.2 Applications References Declarative Data Analysis Using Limit Datalog Programs 1 Introduction 2 Syntax and Semantics of Positive DatalogZ 2.1 Syntax 2.2 Semantics 3 Positive Limit-Linear DatalogZ 3.1 Syntax and Semantics of Limit Programs 3.2 Undecidability and Limit-Linear Programs 3.3 Application Examples 4 Complexity of Positive LL-Programs 4.1 Pseudointerpretations 4.2 Upper Bounds for Positive Programs 4.3 Complexity Lower Bounds for LL-Programs 5 Fragments with Tractable Reasoning 5.1 Stable Positive LL-Programs 5.2 Type-Consistent Programs 6 Related Work 7 Conclusion References Knowledge Graphs: Research Directions 1 Introduction 2 Data Model 3 Queries 4 Ontologies 5 Rules 6 Context 7 Embeddings 8 Graph Neural Networks 9 Conclusions References Author Index