use swi-prolog

Consider the following directed acyclic graph that represents citations between publications. In information science and bibliometrics, a citation graph is a directed graph that describes the citations within a collection of documents. Each vertex (or node) in the graph represents a document in the collection, and each edge (arc) is directed from one document toward another that it cites. For instance, in the given citation graph below, document b cites documents d and e, and document b is cited by document a. 1) Considering nodes (document names) as constants, represent the facts in the given citation graph in Prolog. 2) Represent the following scenario in your Prolog program: a. Two documents are connected if there is a directed path from the first document to the second document in the directed acyclic graph. Is there any specific property that you need to use to define this sentence in your program? What is it? Explain it briefly. Query the SWI-Prolog to show whether document a and document g are connected. Query the SWI-Prolog to show whether document b and document h are connected. Receive the first and the second documents to check the existence of a path between them from the user's keyboard. The output is as follows: Using forward chain reasoning, properly explain the answer of (b) or (c)