by Till Mossakowski, Lutz Schröder and Sergey Goncharov
Abstract:
For a number of programming languages, among them Eiffel, C, Java, and Ruby, Hoare-style logics and dynamic logics have been developed. In these logics, pre- and postconditions are typically formulated using potentially effectful programs. In order to ensure that these pre- and postconditions behave like logical formulae (that is, enjoy some kind of referential transparency), a notion of purity is needed. Here, we introduce a generic framework for reasoning about purity and effects. Effects are modelled abstractly and axiomatically, using Moggi’s idea of encapsulation of effects as monads.We introduce a dynamic logic (from which, as usual, a Hoare logic can be derived) whose logical formulae are pure programs in a strong sense. We formulate a set of proof rules for this logic, and prove it to be complete with respect to a categorical semantics. Using dynamic logic, we then develop a relaxed notion of purity which allows for observationally neutral effects such writing on newly allocated memory.
Reference:
Till Mossakowski, Lutz Schröder and Sergey Goncharov: A Generic Complete Dynamic Logic for Reasoning about Purity and Effects, In Formal Aspects of Computing, 22(3-4), pp. 363–384, 2010.
Bibtex Entry:
@Article{MossakowskiEA09,
author = {Till Mossakowski and Lutz Schr{\"o}der and Sergey Goncharov},
title = {A Generic Complete Dynamic Logic for Reasoning about Purity and Effects},
year = {2010},
journal = {Formal Aspects of Computing},
volume = {22},
pages = {363-384},
number = {3-4},
keywords = {monad logic purity side-effect soundness completeness},
url = {http://dx.doi.org/10.1007/s00165-010-0153-4},
pdfurl = {http://www.informatik.uni-bremen.de/~lschrode/papers/mdl-compl.pdf},
abstract = {For a number of programming languages, among them Eiffel, C, Java, and Ruby, Hoare-style logics
and dynamic logics have been developed. In these logics, pre- and postconditions are typically formulated
using potentially effectful programs. In order to ensure that these pre- and postconditions behave like logical
formulae (that is, enjoy some kind of referential transparency), a notion of purity is needed. Here, we introduce a
generic framework for reasoning about purity and effects. Effects are modelled abstractly and axiomatically, using
Moggi’s idea of encapsulation of effects as monads.We introduce a dynamic logic (from which, as usual, a Hoare
logic can be derived) whose logical formulae are pure programs in a strong sense. We formulate a set of proof
rules for this logic, and prove it to be complete with respect to a categorical semantics. Using dynamic logic, we
then develop a relaxed notion of purity which allows for observationally neutral effects such writing on newly
allocated memory.},
issn = {0934-5043},
status = {Reviewed}
}