Horn Logic Herbrand Semantic Profile of RuleML 1.02

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  • Identifier: http://ruleml.org/1.02/profiles/Horn-Herbrand
  • Syntactic Scope: http://deliberation.ruleml.org/1.02/relaxng/myng-bf-d7-a7-l1-p0-i0-t0-q0-e1-sb.rnc
  • Classification: Herbrand
  • Body:
    • Performatives (Assert, Retract, Query) sequentially induce effects on a dynamic global rulebase.
      • The effect of Assert and Retract is to modify the state of the global rulebase.
      • A "top-level" rulebase (a rulebase without a performative wrapper) is processed as an implicit Assert of that rulebase.
      • Before any performative is applied, the global rulebase is empty.
      • The effect of Assert is to add its formula payload (formulas contained directly or indirectly through a rulebase wrapper) to the global rulebase.
      • The effect of Retract is to (syntactically) subtract its formula payload from the global rulebase.
      • The effect of Query is to generate a query result w.r.t. the global rulebase. The global rulebase itself is unaffected.
        • A query result is either
          • a success, if one or more substitutions for the (zero or more) free variables are entailed by the global rulebase. If the query contains free variables, then additionally the query result may contain a tabulation of these substitutions. If the query contains no free variables, then the tabulation is empty.
          • a failure, if no substitution for the free variables is entailed by the global rulebase.
    • The semantics is defined according to Lloyd[1].
    • The mapping between the logic programming syntax of Lloyd and RuleML/XML syntax as defined as follows:@@@
  • Parent: Predefined Semantic Profiles of RuleML 1.02
  • Example: http://deliberation.ruleml.org/1.02/exa/Hornlog/hornlog/brokerBK.ruleml


  1. Lloyd, J. 1987. Foundations of Logic Programming. 2nd ed. Springer-Verlag. Chapter 2, Section §6. See https://books.google.com/books/about/Foundations_of_Logic_Programming.html?id=P10ZAQAAIAAJ