A rule is known as floor if all of its atoms (head and human body) are floor. A ground rule R1 is a ground instance of another rule R2 if R1 is the results of a substitution of constants for all the variables in R2. The Herbrand foundation of the https://datalog-587530.glifeblog.com/33431499/helping-the-others-realize-the-advantages-of-datalog-5