Step-Indexed Relational Reasoning for Countable Nondeterminism

Programming languages with countable nondeterministic choice are computationally interesting since countable nondeterminism arises when modeling fairness for concurrent systems. Because countable choice introduces non-continuous behaviour, it is well-known that developing semantic models for programming languages with countable nondeterminism is challenging. We present a step-indexed logical relations model of a higher-order functional programming language with countable nondeterminism and demonstrate how it can be used to reason about contextually defined may- and must-equivalence. In earlier step-indexed models, the indices have been drawn from {\omega}. Here the step-indexed relations for must-equivalence are indexed over an ordinal greater than {\omega}

Hydromorphological classification of Slovenian rivers

This paper provides an overview of hydromorphological and related classifications of rivers in Slovenia and elsewhere. The Rosgen classification is presented in greater detail; it was used in the study as the basis for developing the first Slovenian hydromorphological classification. A hydromorphological survey form was designed to classify rivers and used in the office and field survey of hydromorphological variables in the 95 river sections selected in Slovenia. In the river sections studied, hydromorphological types were identified by analyzing the co-occurrence of selected hydromorphological variables. This method was used to identify 10 hydromorphological types, for which the main hydromorphological features are presented in this paper. Based on the results of the first hydromorphological classification of Slovenian rivers, guidelines are provided for future work

Effects of helium and nitrogen as pressurants in nitrogen tetroxide transfer

Study investigates effects of helium and nitrogen as pressurants in nitrogen tetroxide transfer from one vessel to another at a higher elevation. Results may contribute to creation of new environmental systems and improved oxygen solubility in water to promote fish life

Programming and Reasoning with Guarded Recursion for Coinductive Types

We present the guarded lambda-calculus, an extension of the simply typed lambda-calculus with guarded recursive and coinductive types. The use of guarded recursive types ensures the productivity of well-typed programs. Guarded recursive types may be transformed into coinductive types by a type-former inspired by modal logic and Atkey-McBride clock quantification, allowing the typing of acausal functions. We give a call-by-name operational semantics for the calculus, and define adequate denotational semantics in the topos of trees. The adequacy proof entails that the evaluation of a program always terminates. We demonstrate the expressiveness of the calculus by showing the definability of solutions to Rutten's behavioural differential equations. We introduce a program logic with L\"{o}b induction for reasoning about the contextual equivalence of programs.Comment: Version of FoSSaCS 2015 paper with appendice

Habsburške deželnoknežje posesti v notranjosti Istre v luči obračunov iz leta 1439

Leta 1435 je potekla zastava zemljiških gospostev, ki sta jih avstrijska vojvoda Leopold in Ernest februarja in marca 1407 prepustila Reinprechtu II. Walseejskemu kot odškodnino za dolg v višini 32.000 dukatov, med njimi tudi precejšen del centralne Istre obsegajoča Pazinska grofija, ki so jo Habsburžani prejeli leta 1374 z dedovanjem po istrski veji goriških grofov. Prav iz začetka tega obdobja, iz leta 1439 se je ohranila knjiga letnih obračunov habsburških zemljiških gospostev, katere obračuni za gospostva Pazin, Vranja in Završje predstavljajo najstarejši administrativni vir za to ozemlje in nudijo vpogled v upravo in poslovanje z zemljiško posestjo. Gospodarski potencial habsburške komorne posesti v Pazinski grofiji, kot jo dokumentirajo obračuni s konca tridesetih let 15. stoletja, je temeljil predvsem na kmetijski proizvodnji. Med prihodki gospostva so imeli največji pomen vino, žito (predvsem pšenica, rž in oves), drobnica in sir. Celotni letni prihodki habsburške komorne posesti v Istri v letih 1437-1438, so znašali 620 mark 38 soldov, od tega je odpadlo na pazinsko gospostvo 451 m 154 ß, na završko 123 m 96 ß in na vranjsko 46 m 108 ß. Temu nasproti obračuni postavljajo letne izdatke – ki se nanašajo predvsem na plače uradnikov in gradbeno-vzdrževalna dela – v skupni višini 215 m 6 ß; od tega v pazinskem gospostvu 130 m 111 ß, v Vranji 32 m 153 ß in v Završju 51 m 62 ß. Bilanca obravnavanih obračunov kaže okvirni letni dohodek okoli 400 mark beneških soldov, ki so ga Habsburžanom prinašala istrska komorna gospostva, kar – za primerjavo – ustreza približno 10% deležu celotnega habsburškega komornega dohodka na Kranjskem in v Istri

The Guarded Lambda-Calculus: Programming and Reasoning with Guarded Recursion for Coinductive Types

We present the guarded lambda-calculus, an extension of the simply typed lambda-calculus with guarded recursive and coinductive types. The use of guarded recursive types ensures the productivity of well-typed programs. Guarded recursive types may be transformed into coinductive types by a type-former inspired by modal logic and Atkey-McBride clock quantification, allowing the typing of acausal functions. We give a call-by-name operational semantics for the calculus, and define adequate denotational semantics in the topos of trees. The adequacy proof entails that the evaluation of a program always terminates. We introduce a program logic with L\"ob induction for reasoning about the contextual equivalence of programs. We demonstrate the expressiveness of the calculus by showing the definability of solutions to Rutten's behavioural differential equations.Comment: Accepted to Logical Methods in Computer Science special issue on the 18th International Conference on Foundations of Software Science and Computation Structures (FoSSaCS 2015