then all mappings of $ E $ OR law. Many conditions for the existence of a measure are known, but these are far from exhaustive in the problem of norming. Stay tuned with BYJU’S – The Learning App and also explore more videos. Boolean algebras first arose in the studies of G. Boole [1], [2] as a tool of symbolic logic. a set of the form $ \{ {x \in X } : {x \leq u } \} $; 2. bounded above: There exists an element 1, such that a