A brief talk about some features of Maude that might be interesting for the ASCENS project on autonomic component ensembles.

1. maude
Alberto Lluch
ASCENS General Meeting
Pisa, March 2-4, 2011
1
alberto.lluch@imtlucca.it

2. what is maude?
“A high-level, declarative language
that supports both equational
and rewriting logic computation”
– maude.cs.uiuc.edu
2
alberto.lluch@imtlucca.it

3. rule-based
interoperable
semantic framework
reflective
tools unification
3
alberto.lluch@imtlucca.it

4. rule-based
interoperable
semantic framework
reflective
tools unification
4
alberto.lluch@imtlucca.it

5. rule-based
mod m(x) is
import m1, m2,...
sort s1, s2,...
ops f, g,...
eq f(...) = ...
rl l => r
endm
5
alberto.lluch@imtlucca.it

6. rule-based
me
6
alberto.lluch@imtlucca.it

7. rule-based
me me
me me
me me
7
alberto.lluch@imtlucca.it

8. rule-based
interoperable
semantic framework
reflective
tools unification
8
alberto.lluch@imtlucca.it

9. semantic
framework
models of concurrent computation: equational programming, lambda calculi,
Petri nets, process algebras (CCS and pi-calculus), actors, operational
semantics of languages (via K, SOS): Java, C, Python, Haskell, agent
languages, active networks languages, hardware description languages,
logical framework and metatool: linear logic, translations between theorem
provers, type systems, open calculus of constructions, tile logic distributed
architectures and components: UML, OCL, MOF, Service architectures and
middlewares, open distributed processing, models, specification and
analysis of communication protocols: active networks, wireless sensor
networks, firefire leader election protocol, modeling and analysis of
security protocols: cryptographic protocol specification language CAPSL,
MSR, security specification formalism, Maude-NPA, real-time, biological,
probabilistic systems: real-time maude, pathway logic, PMaude
9
alberto.lluch@imtlucca.it

10. semantic
framework
models of concurrent computation: equational programming, lambda calculi,
Petri nets, process algebras (CCS and pi-calculus), actors, operational
semantics of languages (via K, SOS): Java, C, Python, Haskell, agent
languages, active networks languages, hardware description languages,
logical framework and metatool: linear logic, translations between theorem
provers, type systems, open calculus of constructions, tile logic distributed
architectures and components: UML, OCL, MOF, Service architectures and
middlewares, open distributed processing, models, specification and
analysis of communication protocols: active networks, wireless sensor
networks, firefire leader election protocol, modeling and analysis of
security protocols: cryptographic protocol specification language CAPSL,
MSR, security specification formalism, Maude-NPA, real-time, biological,
probabilistic systems: real-time maude, pathway logic, PMaude
10
alberto.lluch@imtlucca.it

11. rule-based
interoperable
semantic framework
reflective
tools unification
11
alberto.lluch@imtlucca.it

12. reflection
 META-LEVEL is a module where
– modules, terms, rules, equations, sorts, etc. are data.
– matching, rule application, rewriting, etc. are functions.
 META-LEVEL is a module so...
it can be treated as data again, and again...
this gives rise to a tower of reflection.
 Metaprogramming applications
– execution layers: ordinary behaviour, reconfiguration, adaptation
– transformation of modules
– analysis of modules
12
alberto.lluch@imtlucca.it

13. reflection
mod AC is
ANALYZE(C) PLAN(C)
crc(C); add(r1,C);
C |= f; del(r2,C);
... ...
mod C is
MEASURE(C,I) EXECUTE(C)
...
read/get(); metaRewrite(C);
endm
endm
13
alberto.lluch@imtlucca.it

14. reflection
me me me me
14
alberto.lluch@imtlucca.it

15. rule-based
interoperable
semantic framework
reflective
tools unification
15
alberto.lluch@imtlucca.it

16. ? ?
x me y
... z me u
16
alberto.lluch@imtlucca.it

17. unification
x me y ≡A z me
Useful for...
 Check confluence of equational specifications (via CPA).
 Model checking ∞-state systems via narrowing.
 Deductive verification
every rule preserves I
I is invariant
 Reason about open systems
– e.g. exploiting semantic frameworks for open processes [Bruni@TCS'07]
17
alberto.lluch@imtlucca.it

18. rule-based
interoperable
semantic framework
reflective
tools unification
18
alberto.lluch@imtlucca.it

19. tools
 Available (tool) checkers for confluence, termination, sufficient completeness,
coherence, reachability, invariants, temporal logic properties, etc.
 Style-Preserving Architectural Reconfigurations (ADR) [Bruni,Montanari,Lluch]
– Correct-by-construction reconfigurations;
– Reconfigurations coordinated by the (hierarchical) structure.
 Hierarchical Graphs for Processes [Bruni,Gadducci,Lluch,Montanari]
– From processes to graphs and back via graph algebras.
 Semantics of long-running transactions (SAGAS) [Bruni,Kersten,Montanari]
– Use of reflection e.g. to install compensations dynamically;
– Maude to simulate and analyse transactional specifications.
 Modal logics for graphs [Corradini,Gadducci,Lluch,Vandin]
– Graph rewriting-like term rewrite rules;
– Temporal graph logic to reason about spatial and temporal properties.
19
alberto.lluch@imtlucca.it

20. rule-based
interoperable
semantic framework
reflective
tools unification
20
alberto.lluch@imtlucca.it

21. interoperability
 MOMENT Project
– Maude simple GUI (textual editor);
– Maude Daemon: Java encapsulation to launch/stop Maude processes.
 MOMENT2
– MOF/OCL/QVT semantics (executable/verifiable);
– MOMENT-MT (model transformations);
– MOMENT-AADL (real-time ADL, real-time Maude).
 Graphical EMF-based editors (under development) [Bruni,Lluch]
– Model-driven methodology to create ad-hoc Maude GUIs;
– Generic Maude graphical editor;
– Object-oriented graphical editor.
21
alberto.lluch@imtlucca.it

22. SO WHAT?
22
alberto.lluch@imtlucca.it

23. maude role
 None
“this thing is completely useless for me”
 A WP2 model “debugger”
“check model definitions and results”
 An interpreter/analyser for some SCEL dialect
“double-check the semantics to discover ambiguities”
 An inspiration for models
“reflective knowledge, stochastic unification, etc.”
23
alberto.lluch@imtlucca.it