A List by Author: Libor Škarvada

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A Calculus of Coercive Subtyping

by Matej Kollár, Ondřej Peterka, Ondřej Ryšavý, Libor Škarvada, November 2009, 17 pages.

FIMU-RS-2009-11. Available as Postscript, PDF.


This report deals with a type system that merges subtyping and dependent types. We define a calculus that instead of term overloading employs coercion mappings. This enables to detach the subtyping from other parts of the calculus, so that the mutual dependence between subtyping, typing and kinding can be reduced. We analyze basic properties of the calculus and show several examples that demonstrate the mechanism of coercive subtyping.

Modelling Dialogue Systems by Finite Automata

by Ivan Kopeček, Libor Škarvada, March 2003, 13 pages.

FIMU-RS-2003-01. Available as Postscript, PDF.


Based on finite state formalization, this paper deals with the problem of modelling and automatic programming of dialogue systems. The approach presented here is based on finding an operator (a construction) that assigns a corresponding dialogue system to a dialogue corpus. It will be shown that this construction is universal, in the sense that each dialogue system can be obtained in this way, and some related issues (uniqueness, algorithmization and algorithmical complexity) will be briefly discussed. The theory is illustrated on a simple example. Some related problems are formulated.