[Con preghiera di diffusione e scuse per l'eventuale ricezione di copie
multiple. RB]
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Date: Mercoledi`, 2 febbraio 2005
Time: 14:30
Speaker: Pedro Vasconcelos
School of Computer Science
University of St Andrews
North Haugh, St Andrews, UK
Title: A Type and Effect System for Cost Equation Synthesis
Abstract: We present a static program analysis based on an annotated
type system for synthesising size and cost recurrences for a
minimal functional notation (simply-typed lambda-calculus
with naturals, lists and recursive definitions). The cost
recurrences express upper-bound aproximations on the number
of beta-reductions in a call-by-value operational semantics.
This work is being developed is part of the research in
``Hume'', a functionally-inspired programming language for
resource-bounded systems (http://www.hume-lang.org).
Place: Sala Riunioni
Dipartimento di Matematica
Universita` di Parma
Via D'Azeglio, 85/A
Parma
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Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara@cs.unipr.it
CVSROOT: /cvs/purrs
Module name: purrs
Changes by: pescetti(a)cs.unipr.it 2005-01-27 01:22:43
Modified files:
tests : multivar_driver.cc
Log message:
Make sure we give symbols their original name after processing.
Removed unused code.
Patches:
http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/purrs/tests/multivar_driver.cc.di…
CVSROOT: /cvs/purrs
Module name: purrs
Changes by: pescetti(a)cs.unipr.it 2004-12-12 13:03:52
Added files:
infrastructure : depinst
Log message:
Script to install the PURRS dependencies. Not for general use, but
can be helpful to test new GCC versions and for fresh installs.
Many known limitations (see comments in script).
Patches:
http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/purrs/infrastructure/depinst?cvsr…
CVSROOT: /cvs/purrs
Module name: purrs
Changes by: zaccagnini(a)cs.unipr.it 2004-11-20 18:11:03
Modified files:
tests : heap
Log message:
Added a new linear recurrence of order 2 arising from a
number-theoretical problem. Notice that the order-reduction method
backfires, in that it finds an expression for the solution which is
more complex than it should be. When the initial conditions are
"x(0) = 0" and "x(1) = 9", the solution found without the reduction
is, indeed, "x(n) = (4 / 5 * n + 1) * 5^n".
The more general, and more interesting, relation
x(n) = p^2 * x(n-2) + 2 * (p - 1) / p * p^n
is marked as "too complex". This phenomenon should be investigated,
since PURRS ought to be able to solve the general case as well as
special ones.
The relevant initial conditions are "x(0)=1" and "x(1) = 2 * p - 1",
and the solution is "x(n) = ((p - 1) / p * n + 1) * p^n"
Patches:
http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/purrs/tests/heap.diff?cvsroot=pur…
