Hermann K.-G. Walter

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Promise problems have been introduced in 1985 by S.Even e.a. as a generalization of decision problems. Using a very general approach we study solvability and unsolvability conditions for promise problems of set families and languages. We show, that cores of un-solvability are completely determined by partitions of cohesive sets. We prove the existence of(More)
A new upper limit for the probability of spontaneous muonium to antimuo-nium conversion was established at P MM ≤ 8.2 · 10 −11 (90%C.L.) in 0.1 T magnetic field, which implies consequences for speculative extensions to the standard model. Coupling parameters in R-parity violating supersymmetry and the mass of a flavour diagonal bileptonic gauge boson can be(More)
Classification problems have been introduced by M. Ziegler as a generalization of promise problems. In this paper we are concerned with solvability and unsolvability questions with respect to a given set or language family, especially with cores of unsolvability. We generalize the results about unsolvability cores in promise problems to classification(More)