OASIS TC Open Repository: Manages TOSCA profiles, tests, and templates that are maintained by the TOSCA community. They are intended to be used as examples to help developers get started with TOSCA and to test compliance of TOSCA implementations with the standard.
https://docs.oasis-open.org/tosca/TOSCA/v2.0/csd05/TOSCA-v2.0-csd05.html#_Toc125468802 documents function definition syntax, but the syntax suggested for
function refinementneeds further clarification/exploration, since refinements in function definitions does not follow the same pattern as refinement in type definitions