Implementing graph grammars for intelligence analysis in OCaml

We report on implementing graph grammars for intelligence analysis in OCaml. Graph grammars are represented as elements of an algebraic data type in OCaml. In addition to algebraic data types, we use other concepts from functional programming languages to implement features of graph grammars. We use type checking to perform graph pattern matching. Graph transformations are defined as implicit coercions derived from structural subtyping proofs, subset types, lambda abstractions, and analytics. An analytic is a general-purpose OCaml function whose output is required to match a graph pattern described by an element of an algebraic data type. By using a strongly-typed language for representing graphs, we can ensure graphs produced from a graph transformation will match a specific schema. This is a high priority requirement for intelligence analysis.