A rule known as ground if all of its atoms (head and entire body) are ground. A floor rule R1 is usually a floor instance of A further rule R2 if R1 is the results of a substitution of constants for many of the variables in R2. The Herbrand foundation https://integratedmanagementsyste88765.goabroadblog.com/33161916/helping-the-others-realize-the-advantages-of-datalog