Abstract state machines capture parallel algorithms: Correction and extension

State Machines Capture Parallel Algorithms: Correction and Extension ANDREAS BLASS University of Michigan and YURI GUREVICH Microsoft Research We consider parallel algorithms working in sequential global time, for example circuits or parallel random access machines (PRAMs). Parallel abstract state machines (parallel ASMs) are such parallel algorithms, and the parallel ASM thesis asserts that every parallel algorithm is behaviorally equivalent to a parallel ASM. In an earlier paper, we axiomatized parallel algorithms, proved the ASM thesis and proved that every parallel ASM satisfies the axioms. It turned out that we were too timid in formulating the axioms; they did not allow a parallel algorithm to create components on the fly. This restriction did not hinder us from proving that the usual parallel models, like circuits or PRAMs or even alternating Turing machines, satisfy the postulates. But it resulted in an error in our attempt to prove that parallel ASMs always satisfy the postula...

• Type: Journal
• Year: 2008
• Where: TOCL
• Authors: Andreas Blass, Yuri Gurevich
• Keywords: Parallel Algorithms, Parallel Asm Thesis, Parallel Asms, TOCL 2008