A Constructor-Based Approach to Positive/Negative-Conditional Equational Specifications

  title={A Constructor-Based Approach to Positive/Negative-Conditional Equational Specifications},
  author={Claus-Peter Wirth and Bernhard Gramlich},
  journal={J. Symb. Comput.},
We study algebraic specifications given by finite sets R of positive/negative-conditional equations (i.e. universally quantified first-order implications with a single equation in the succedent and a conjunction of positive and negative (i.e. negated) equations in the antecedent). The class of models of such a specification R does not contain in general a minimum model in the sense that it can be mapped to any other model by some homomorphism. We present a constructor-based approach for… 
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