Knowledge representation; Graph formal language; Clausal form logics RDF model; Semantic web; Linked data

It is a fact that the RDF(S) model has been declared as the ground base for implementations of further web development conception. RDF provides a common and flexible way to decompose knowledge to elementary statements that allows, as networks of indivisible knowledge atoms, to be represented by RDF triples or by RDF graph vectors.The article presents two graph based formal systems GRDF and RDFCFL defined on the base of extended RDF model with the help of clausal form logic principle and notation. The transformation process from the first order predicate logics (FOPL) to the RDF graph notation protects language expressivity and moreover both the presented systems share the partial decidability with the FOPL. As an example it is shown a reasoning of consequents in a monotonic version of the RDFCFL system.