A method to process subroutine-structured graph-based intermediate representations during formal language processing implemented by a computing device. The method includes classifying a set of subroutines identified in an intermediate representation of code according to mutually recursive relationships between subroutines in the set of subroutines, recording the mutually recursive relationships, labeling to track the mutually recursive relationships, constructing a set of graph representations, collecting partial positions that distinguish points of action in generated code, labeling nodes of the graph of the intermediate representation, generating a subsequent intermediate representation by serialization of the graph of the intermediate representation through pre-order depth-first traversal, and creating the generated code from the intermediate representation.