por José Nuno Oliveira, HASLab-DI-UMinho
No dia 5 de novembro, pelas 15h00, na sala FC6 029 do DCC-FCUP, José Nuno Oliveira irá dar uma palestra intitulada "How much is in a type? Calculating functional programs from their types using squares". A palestra é organizada pelo DCC-FCUP.
Às 14h, na mesma sala, será transmitida a palestra online One FLAT World Seminar, "Computational model for parsing expression grammars" (por Alexander Rubtsov).
Short Bio
José Nuno Oliveira is a Professor of Computer Science at the Informatics Department of the University of Minho and a researcher at HASLab/INESC TEC. His research aims at improving scientific standards in software design through formal methods and calculational techniques. These include the application of mathematical transforms in refactoring and improving existing software theories. He does this with passion and firmly believes this will make computing better in the future.
Title
How much is in a type? Calculating functional programs from their types using squares
Abstract
Experience in teaching functional programming on a relational basis has led me to focus on a graphical style of expression and reasoning in which a geometric construct shines: the (semi) commutative square. In the classroom this is termed the “magic square” (MS), since virtually everything that we do in logic, functional programming, database modelling, formal semantics and so on fits in some MS geometry. MSs compose and have a number of useful properties. Among several examples ranging over different application domains, free-theorem MSs are shown to be particularly elegant and productive. Helped a little bit by Galois connections, a generic, induction-free theory for foldr and foldl is given, showing in particular that foldl s = foldr (flip s) holds under conditions milder than usually advocated.