Full Idea
The common feature of every designating term is that designation may change from state to state - thus it can be formalized by a function from states to objects.
Gist of Idea
If terms change their designations in different states, they are functions from states to objects
Source
Melvin Fitting (Intensional Logic [2007], 3)
Book Reference
'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.8
A Reaction
Specifying the objects sounds OK, but specifying states sounds rather tough.