Computer-implemented method, computer system, and computer program product for optimization of evaluation of a policy specification

A computer program product that includes a non-transitory computer-readable medium comprising computer-readable instructions, which when executed by a computer system, cause the computer system to perform operations including:

• receiving the policy specification represented as a tree, the tree comprising a plurality of nodes;
• determining a visiting history of the tree, wherein the visiting history is determined by computing a density at least for each node in a subset of the plurality of nodes having been visited, wherein the density is determined by a relationship between a position of a node v in the tree and a frequency F(v) in which the node v is visited;
• and
• transforming the tree with respect to the visiting history into a similar tree such that sibling nodes in the subset of the plurality of nodes are sorted in decreasing order according to their density, the similar tree being a minimum cost tree of all similar trees of the tree, and the minimum cost characterizing a minimum cost to reach each node of the similar tree with a weighting corresponding to a frequency at which said each node is visited in the visiting history of the tree.

A computer system to optimize evaluation of a policy specification, the computer system comprising a computer configured to perform operations for a computer implemented component, the computer-implemented component being operable to:

• receive the policy specification represented as a tree, the tree comprising a plurality of nodes;
• determine a visiting history of the tree, wherein the visiting history is determined by computing a density at least for each node in a subset of the plurality of nodes having been visited, wherein the density is determined by a relationship between a position of a node r in the tree and a frequency F(v) in which the node v is visited;
• and
• transform the tree with respect to the visiting history into a similar tree such that sibling nodes in the subset of the plurality of nodes are sorted in decreasing order according to their density, the similar tree being a minimum cost tree of all similar trees of the tree, and the minimum cost characterizing a minimum cost to reach each node of the similar tree with a weighting corresponding to a frequency at which said each node is visited in the visiting history of the tree.