--%>

Problem on Datalog for defining properties

The focus is on  the use of Datalog for defining properties  and queries on graphs.

(a) Assume that P is some property of graphs  definable in the Datalog. Show that P is preserved beneath extensions  and homomorphisms. That is, when G is a graph satisfying P, then for every supergraph of G (i.e., graph  extending G) satisfies  P, and  when h is a graph homomorphism, then h(G) satisfies P. Which of the below properties  and queries on graphs are definable in the Datalog?

(b) The number  of vertices  are even.

(c) There is a simple path (that is, a path without repeated vertices) of even length among two specified vertices.

(d) The binary relation? Having all pairs of vertices (a, b) for which  there  is a path of even length from a to b.

Given either a Datalog program stating the property or query or an argument why the property or query is not definable in the Datalog.

   Related Questions in Mathematics

  • Q : Set Theory & Model of a Boolean Algebra

    II. Prove that Set Theory is a Model of a Boolean Algebra The three Boolean operations of Set Theory are the three set operations of union (U), intersection (upside down U), and complement ~.  Addition is set

  • Q : Problem on budgeted cash collections

    XYZ Company collects 20% of a month's sales in the month of sale, 70% in the month following sale, and 5% in the second month following sale. The remainder is not collectible. Budgeted sales for the subsequent four months are:     

  • Q : Problem on mixed-strategy equilibrium

    Assume three Offices (A, B, & C) in downtown,  simultaneously decide whether to situate in a new Building. The payoff matrix is illustrated below. What is (are) the pure stratgy Nash equilibrium (or equilibria) and mixed-strtegy equilibrium of the game?

  • Q : Elementary Logic Set & Model of a

    Prove that Elementary Logic Set is a Model of a Boolean Algebra The three Boolean operations of Logic are the three logical operations of  OR ( V ), AN

  • Q : Competitive equilibrium 8. Halloween is

    8. Halloween is an old American tradition. Kids go out dressed in costume and neighbors give them candy when they come to the door. Spike and Cinderella are brother and sister. After a long night collecting candy, they sit down as examine what they have. Spike fi

  • Q : Who independently developed

    Who independently developed a model for simply pricing risky assets?

  • Q : Logic and math The homework is attached

    The homework is attached in the first two files, it's is related to Sider's book, which is "Logic for philosophy" I attached this book too, it's the third file.

  • Q : Who derived the Black–Scholes Equation

    Who derived the Black–Scholes Equation?

  • Q : Numerical Analysis Hi, I was wondering

    Hi, I was wondering if there is anyone who can perform numerical analysis and write a code when required. Thanks

  • Q : How do it? integral e^(-t)*e^(tz) t

    integral e^(-t)*e^(tz) t between 0 and infinity for Re(z)<1