Correctness of mixed computation in ALGOL-like programs

Abstract

Three schemes of mixed computation have been defined and studied: mix, $\overline{\overline {mix}} and\mathop {mix}\limits^\bigcirc$. For a given R₁, the following inclusions take place: $ssv (mix) \subseteq ssv (\overline{\overline {mix}} ) \subseteq ssv\mathop {(mix}\limits^\bigcirc )$. The processes $\overline{\overline {mix}} and\mathop {mix}\limits^\bigcirc$are correct in the general case, mix is more effective but requires a kind of memory protection.

In all three processes, suspended statements and trains are attached to the extending residual program without any modification. However, an evaluation of some functional and predicate terms is possible in a suspended statement or train that can greatly simplify the residual program. This and some other optimizations in mixed computation are the subject of further study.