%0 Journal Article
%@ 0304-3975
%A De Nicola, Rocco
%A Segala, Roberto
%D 1995
%F eprints:366
%I Elsevier
%J Theoretical Computer Science
%N 2
%P 391-423
%T A Process Algebraic View of Input/Output Automata
%U http://eprints.imtlucca.it/366/
%V 138
%X Input/output automata are a widely used formalism for the specification and verification of concurrent algorithms. Unfortunately, they lack an algebraic characterization, a formalization which has been fundamental for the success of theories like CSP, CCS and ACP. We present a many-sorted algebra for I/O automata that takes into account notions such as interface, input enabling, and local control. It is sufficiently expressive for representing all finitely branching transition systems; hence, all I/O automata with a finitely branching transition relation. Our presentation includes a complete axiomatization of the external trace preorder relation over recursion-free processes with input and output.