Sound rules for parallel evaluation of a functional language with callcc

Observationally equivalent programs are programs which are indistinguishable in all contexts, as far as their termination property is concerned. In this paper, we present rules preserving observational equivalence, for the parallel evaluation of programs using call/cc. These rules allow the capture of continuations in any applicative context and they prevent from aborting the whole computation when a continuation is applied in the extent of the call/cc by which it was reified. As a consequence, these results prove that one can design a functional language with first-class continuations which has transparent constructs for parallelism