Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

Expressiveness of streaming string transducers Rajeev Alur1

Summary: Expressiveness of streaming string transducers
Rajeev Alur1
and Pavol Cernư2
1 University of Pennsylvania
2 IST Austria
Streaming string transducers [1] define (partial) functions from input strings to output strings.
A streaming string transducer makes a single pass through the input string and uses a finite
set of variables that range over strings from the output alphabet. At every step, the transducer
processes an input symbol, and updates all the variables in parallel using assignments whose
right-hand-sides are concatenations of output symbols and variables with the restriction that
a variable can be used at most once in a right-hand-side expression. It has been shown that
streaming string transducers operating on strings over infinite data domains are of interest in
algorithmic verification of list-processing programs, as they lead to Pspace decision procedures
for checking pre/post conditions and for checking semantic equivalence, for a well-defined class of
heap-manipulating programs. In order to understand the theoretical expressiveness of streaming
transducers, we focus on streaming transducers processing strings over finite alphabets, given the
existence of a robust and well-studied class of "regular" transductions for this case. Such regular
transductions can be defined either by two-way deterministic finite-state transducers, or using
a logical MSO-based characterization. Our main result is that the expressiveness of streaming


Source: Alur, Rajeev - Department of Computer and Information Science, University of Pennsylvania


Collections: Computer Technologies and Information Sciences