--%>

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 : Linear programming model of a Cabinet

    A cabinet company produces cabinets used in mobile and motor homes. Cabinets produced for motor homes are smaller and made from less expensive materials than those for mobile homes. The home office in Dayton Ohio has just distributed to its individual manufacturing ce

  • Q : Problem on sales and budget XYZ Farm

    XYZ Farm Supply data regarding the store's operations follow: • Sales are budgeted at $480,000 for November, $430,000 for December, and $340,000 for January. • Collections are expected

  • Q : Theorem-G satis es the right and left

    Let G be a group. (i) G satis es the right and left cancellation laws; that is, if a; b; x ≡ G, then ax = bx and xa = xb each imply that a = b. (ii) If g ≡ G, then (g-1)

  • Q : Uniform scaling what is uniform scaling

    what is uniform scaling in computer graphic

  • Q : Explain Factorisation by trial division

    Factorisation by trial division: The essential idea of factorisation by trial division is straightforward. Let n be a positive integer. We know that n is either prime or has a prime divisor less than or equal to √n. Therefore, if we divide n in

  • Q : Budgeted cash disbursements The ABC

    The ABC Company, a merchandising firm, has budgeted its action for December according to the following information: • Sales at $560,000, all for cash. • The invoice cost for goods purc

  • Q : Problem on Prime theory Suppose that p

    Suppose that p and q are different primes and n = pq. (i) Express p + q in terms of Ø(n) and n. (ii) Express p - q in terms of p + q and n. (iii) Expl

  • Q : Properties of a group How can we say

    How can we say that the pair (G, o) is a group. Explain the properties which proof it.

  • Q : Problem on Linear equations Anny, Betti

    Anny, Betti and Karol went to their local produce store to bpought some fruit. Anny bought 1 pound of apples and 2 pounds of bananas and paid $2.11.  Betti bought 2 pounds of apples and 1 pound of grapes and paid $4.06.  Karol bought 1 pound of bananas and 2

  • Q : Breakfast program if the average is

    if the average is 0.27 and we have $500 how much break fastest will we serve by 2 weeks