A Compositional Approach for Fault-Tolerance Using Specification Transformation

The incorporation of a recovery algorithm into a program can be viewed as a program transformation, converting the basic program into a fault-tolerant version. We present a framework in which such program transformations are accompanied by a corresponding formula transformation which obtains properties of the fault-tolerant versions of the programs from properties of the basic programs. Compositionality is achieved when every property of the fault-tolerant version can be obtained from a transformed property of the basic program.