Abstract Machine for a Comonadic Dataflow Language

The formal semantics of higher-order functional dataflow language programs can be represented with the concepts of arrows and comonads from category theory. Both of these methods convey the meaning of programs, but not the operational behaviour of them. In order to understand the operational behaviour of dataflow programs we will derive an abstract machine from an interpreter that is equivalent to a comonadic denotational semantics of a higher-order call-by-name dataflow language. The resulting abstract machine is identical to the well known abstract machine by Krivine with the exception of an overloaded notion of the environment and two additional transition rules for evaluating constructs specific to the dataflow language. The main result of this thesis is that the operational behaviour of call-by-name dataflow language programs is identical to the operational behaviour of regular non-strict languages

First observed wild birth and acoustic record of a possible infanticide attempt on a common bottlenose dolphin (Tursiops truncatus)

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Society for Marine Mammalogy for personal use, not for redistribution. The definitive version was published in Marine Mammal Science 32 (2016): 376–385, doi:10.1111/mms.12248.We observed the birth of a common bottlenose dolphin (Tursiops truncatus) followed immediately by a possible infanticide attempt in the estuary near Savannah, Georgia. Our report is unique in several ways: first, we witnessed the birth of the calf; second, we observed infanticidal behavior almost immediately afterward; and third, we obtained acoustic recordings concurrent with the possible infanticidal behavior. Our observations provide insight into aggressive, possible infanticidal, behavior in bottlenose dolphins.Boat time and support was provided by Department of Education/Title VII Award P382G090003. Additional support was provided by EDGE (Enhancing Diversity in Geosciences Education through Costal Research in Port City) NSF award GEO-0194680.2016-07-1

Particpants' Proceedings on the Workshop: Types for Program Analysis

As a satellite meeting of the TAPSOFT'95 conference we organized a small workshop on program analysis. The title of the workshop, ``Types for Program Analysis´´, was motivated by the recent trend of letting the presentation and development of program analyses be influenced by annotated type systems, effect systems, and more general logical systems. The contents of the workshop was intended to be somewhat broader; consequently the call for participation listed the following areas of interest:- specification of specific analyses for programming languages,- the role of effects, polymorphism, conjunction/disjunction types, dependent types etc.in specification of analyses,- algorithmic tools and methods for solving general classes of type-based analyses,- the role of unification, semi-unification etc. in implementations of analyses,- proof techniques for establishing the safety of analyses,- relationship to other approaches to program analysis, including abstract interpretation and constraint-based methods,- exploitation of analysis results in program optimization and implementation.The submissions were not formally refereed; however each submission was read by several members of the program committee and received detailed comments and suggestions for improvement. We expect that several of the papers, in slightly revised forms, will show up at future conferences. The workshop took place at Aarhus University on May 26 and May 27 and lasted two half days

Normalization by Evaluation for Call-by-Push-Value and Polarized Lambda-Calculus

We observe that normalization by evaluation for simply-typed lambda-calculus with weak coproducts can be carried out in a weak bi-cartesian closed category of presheaves equipped with a monad that allows us to perform case distinction on neutral terms of sum type. The placement of the monad influences the normal forms we obtain: for instance, placing the monad on coproducts gives us eta-long beta-pi normal forms where pi refers to permutation of case distinctions out of elimination positions. We further observe that placing the monad on every coproduct is rather wasteful, and an optimal placement of the monad can be determined by considering polarized simple types inspired by focalization. Polarization classifies types into positive and negative, and it is sufficient to place the monad at the embedding of positive types into negative ones. We consider two calculi based on polarized types: pure call-by-push-value (CBPV) and polarized lambda-calculus, the natural deduction calculus corresponding to focalized sequent calculus. For these two calculi, we present algorithms for normalization by evaluation. We further discuss different implementations of the monad and their relation to existing normalization proofs for lambda-calculus with sums. Our developments have been partially formalized in the Agda proof assistant

The Polygram, November 1916

Student newspaper of California Polytechnic State University, San Luis Obispo, CA.https://digitalcommons.calpoly.edu/studentnewspaper/1014/thumbnail.jp

The Polygram, November 1916

Student newspaper of California Polytechnic State University, San Luis Obispo, CA.https://digitalcommons.calpoly.edu/studentnewspaper/1015/thumbnail.jp