The work concerned the assembly of biological sub-systems to gain access to a functional representation of the overall system, in the case of complex biological interactions (symbiosis, etc.). The proposed method uses the statement of expert knowledge described in a literal way to establish the sub-system interface program. The use of interrogative pronouns and adverbs provides a formal framework to produce graphs from literal descriptions. In terms of results, the method enables (i) access to the vocabulary of the assembly program, (ii) identification of the transformation functions to be established, and (iii) an estimation of the valence required by programs to ensure assembly. From an operational perspective, the generic approach proposed is a theoretical construct that remains to be validated in concrete cases of application.