Halliday & Matthiessen (1999: 13):
We have said that the ideation base is a resource for construing our experience of the world. Such construal is both paradigmatic and syntagmatic. (i) In paradigmatic construal, we construe a phenomenon as being of some particular type — some selection from a set of potential types. The ideation base is in fact organised as a network of inter-related types of phenomena, (ii) In syntagmatic construal, we construe a phenomenon as having some particular composition — as consisting of parts in some structural configuration.
For example, if some phenomenon is construed as belonging to the type 'creative doing', it will configure as an Actor, a Process, and a Goal which is brought into existence through the actualisation of the Process, These two modes of construal are related: on the one hand, syntagmatic organisation realises paradigmatic organisation; on the other hand, types in the network of paradigmatic organisation correspond to fragments of syntagmatic specification — this is one way in which such types are differentiated.