5 papers
From Time to Space: The Impact of Linearity in Higher-Order Datalog
Angelos Charalambidis, Babis Kostopoulos, Panos Rondogiannis
We consider a fragment of Higher-Order Datalog with negation and argue that it generalizes the familiar and important fragment of Linear Datalog. We investigate the expressive powe…
Equilibrium Semantics and Strong Equivalence for Higher-Order Logic Programs
Angelos Charalambidis, Giannos Chatziagapis, Babis Kostopoulos +1
One of the most significant achievements of equilibrium logic was the characterization of strong equivalence, a property crucial for program transformation and optimization in Answ…
The Power of Negation in Higher-Order Datalog
Angelos Charalambidis, Babis Kostopoulos, Christos Nomikos +1
We investigate the expressive power of Higher-Order Datalog under both the well-founded and the stable model semantics, establishing tight connections with complexity classe…
Dealing with Inconsistency for Reasoning over Knowledge Graphs: A Survey
Anastasios Nentidis, Charilaos Akasiadis, Angelos Charalambidis +1
In Knowledge Graphs (KGs), where the schema of the data is usually defined by particular ontologies, reasoning is a necessity to perform a range of tasks, such as retrieval of info…
Recursive Function Definitions in Static Dataflow Graphs and their Implementation in TensorFlow
Kelly Kostopoulou, Angelos Charalambidis, Panos Rondogiannis
Modern machine learning systems represent their computations as dataflow graphs. The increasingly complex neural network architectures crave for more powerful yet efficient program…