Recovering Incidence Functions

In incidence calculus inferences are usually made by calculating incidence sets and computing probabilities of formulae based on a given incidence function in an incidence calculus theory Incidence functions are vital for performing any further inference Without the existence of this function many of the features of incidence cal culus will be lost However it is still the case that numerical values are assigned on some formulae directly without giving the incidence function This paper discusses how to recover incidence functions in these cases The result can be used to calculate mass functions from belief functions in the Dempster Shafer theory of evidence or DS theory and de ne probability spaces from inner measures or lower bounds of probabilities on the relevant propositional language set