In the final part of the chapter we consider non-linear temporal logics based on just reflexive and transitive time flow (which do not implement operations UNTIL and NEXT) with interpretations of Chance Discovery and Uncertainty. Such logics are also decidable. Our results may be classified as construction of mathematical models for CD and Uncertainty, development of logical theory for CD and Uncertainty; they might be useful for researchers interested in logical properties of CD and Uncertainty within AI paradigms.