Closure of basic role DP-model

Two kinds of access graph closure are defined here for the role DP-model, and algorithms for the construction of them are suggested in the paper. The results are aimed to verify for all the users, entities and access rights simultaneously if the predicate $can\_share()$ is true meaning the possibility of taking ownership access rights of a trusted subject by an untrusted subject in a computer system with discretionary access and information stream management.