--%>

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 : Calculus I need it within 4 hours. Due

    I need it within 4 hours. Due time March 15, 2014. 3PM Pacific Time. (Los Angeles, CA)

  • Q : Problem on Maple (a) Solve the

    (a) Solve the following  by: (i) First reducing the system of first order differentiat equations to a second order differential equation. (ii) Decoupling the following linear system of equa

  • 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 : Global And Regional Economic Development

    The Pharmatec Group, a supplier of pharmaceutical equipment, systems and services, has its head office in London and primary production facilities in the US. The company also has a successful subsidiary in South Africa, which was established in 1990. Pharmatec South A

  • Q : Probability and Stochastic assignment

    Introduction to Probability and Stochastic Assignment 1: 1. Consider an experiment in which one of three boxes containing microchips is chosen at random and a microchip is randomly selected from the box.

  • Q : Maths A cricketer cn throw a ball to a

    A cricketer cn throw a ball to a max horizontl distnce of 100m. If he throws d same ball vertically upwards then the max height upto which he can throw is????

  • Q : Uniform scaling what is uniform scaling

    what is uniform scaling in computer graphic

  • Q : Problem on inverse demand curves In

    In differentiated-goods duopoly business, with inverse demand curves: P1 = 10 – 5Q1 – 2Q2P2 = 10 – 5Q2 – 2Q1 and per unit costs for each and every firm equal to 1.<

  • Q : Use MS Excel to do the computations

    Select a dataset of your interest (preferably related to your company/job), containing one variable and atleast 100 data points. [Example: Annual profit figures of 100 companies for the last financial year]. Once you select the data, you should compute 4-5 summary sta

  • Q : The mean of the sampling distribution

    1. Caterer determines that 87% of people who sampled the food thought it was delicious. A random sample of 144 out of population of 5000 taken. The 144 are asked to sample the food. If P-hat is the proportion saying that the food is delicious, what is the mean of the sampling distribution p-hat?<