The Function Ontology is a way to semantically declare and describe functions, without depending on the implementation.
In-Use: Declarative Data Transformations for Linked Data Generation: The Case of DBpedia
An Ontology to Semantically Declare and Describe Functions
Detailed Provenance Capture of Data Processing
Framework: Discovering and Using Functions via Content Negotiation
Connection to RML
Connection to RML and PROV