A notion developed by Elizabeth Closs Traugott in work on semantic change and applied and developed in the theory of principled polysemy in attempting to account for how chaining takes place in a semantic network. Takes a usage-based perspective on chaining: context-dependent inferences associated with a given word are reanalyzed as distinct meanings. Through a process of strengthening, these 'new' meanings come to be stored as distinct senses or lexical concepts in semantic memory. This process is thus referred to as pragmatic strengthening. For instance, Vyvyan Evans and Andrea Tyler in their work on English prepositions argue that pragmatic strengthening gives rise to the development of new prepositional meanings. In an utterance such as: The tablecloth is over the table, a context-dependent inference is that a consequence of the tablecloth being 'over' (i.e. 'above'), the table it also covers the table. The inference of 'covering' has, via reanalysis and strengthening, come to be stored in long-term memory as a distinct 'covering' meaning conventionally indexed by the form over. Evans and Tyler argue that it is for this reason that over can be used to mean 'covering' even where over does not have an 'above' reading, as in examples such as: The clouds are over the sun.