In order to simplify things even further at the beginning, we consider the definition of symbiosis to be the living together of any optimizations. Thereby we also rule out, that the definition is too narrow. The optimizations may be represented by actual living beings or just its genes, but computer programs and their source code are also considered as such in this context.
Why can software be considered a living being? What is life? Compare software to viruses, that is also considered life in this context.