The most well known and central component of SFL accounts remains the system network The system network is the one component that can be found in all computational accounts of SFL and corresponding computational tools. There are, however, some differences in how the networks are defined and several differences in how they are displayed to users. Networks typically contain, or are linked with, realization statements that describe the syntagmatic consequences of collections of paradigmatic options. Different computational models often differ with respect to the particular realization statements that they provide. Part of a standardization effort will be to explore those differences more closely and to find, where possible, correspondences. Some tools do not provide any explicit notion of realization statements: these cannot therefore represent information across the paradigmatic-syntagmatic axis.
The following represent distinct styles of system network definition: