Bergstra, J. A., Hirshfeld, Y., Tucker, J. V.
A skew meadow is a non-commutative ring with an inverse operator satisfying two special equations and in which the inverse of zero is zero. All skew fields and products of skew fields can be viewed...
Meadows and the equational specification of division (2009)
Bergstra, J. A., Hirshfeld, Y., Tucker, J. V.
The rational, real and complex numbers with their standard operations, including division, are partial algebras specified by the axiomatic concept of a field. Since the class of fields cannot be...
Decidable Subsets of CCS (1994)
Christensen, S., Hirshfeld, Y., Moller, F.
CCS is a universal formalism: any computable function is computed by some CCS agent. Moreover, one can reduce the halting problem for Turing machines to the problem of deciding bisimilarity of two...