CLiFF Notes

Notes on Heat Transfer in a Layered Longeron

Thinking Tools for the Future of Computing Science

This paper argues that “formal methods” can (continue to) provide the thinking tools for the future of computing science. Every significant engineering or scientific discipline has advanced only with systematic and formally based notations. To see just how ubiquitous the need for notation is, one can look beyond the sciences and observe the importance of written notation in the development of m...

A Formal Basis for Some Dependability Notions

This paper shows how formal methods ideas can be used to clarify basic notions used in the field of dependability. Central to this endeavour is fixing a notion of system. Relationships between systems are also considered: in particular, the importance of the situation where one system is generated by another (possibly human) system is explored. The formalisation is used as a basis for definitio...

Research in the Language, Information and Computation Laboratory of the University of Pennsylvania

This report takes its name from the Computational Linguistics Feedback Forum (CLiFF), an informal discussion group for students and faculty. However the scope of the research covered in this report is broader than the title might suggest; this is the yearly report of the LINC Lab, the Language, Information and Computation Laboratory of the University of Pennsylvania. It may at first be hard to ...

Reasoning About Partial Functions in the Formal Development of Programs

Partial functions and operators are used extensively in the formal development of programs and thus development methods have to clarify how to reason about them. There are a number of approaches which cover up the fact that “First Order Predicate Calculus” does not handle undefined logical values. There is also at least one specific “Logic of Partial Functions” (LPF) which tackles the issue at ...