Quiz. Finding recursive Horn clauses [004z]

  • December 16, 2025

Is the following set of horn clauses recursive?

  1. \[ \begin {align} q(x) \land r(x) &\to p(x) \\ p(x) \land (x < n) &\to \bot \end {align} \]
  2. \[ \begin {align} q(x) \land r(x) &\to p(x) \\ p(x) \land (x > 0) &\to r(x) \\ p(x) \land (x < n) &\to \bot \end {align} \]

Solution. 

  • December 16, 2025
  1. No, we can draw the dependency graph as follows
  2. Yes, because the head \(p\) depends on the query \(r\) and vv. again as a graph we can draw it as follows