By Elisabeth Egan Aaron Robertson’s grandparents had a farm in Promise Land, Tenn. In a new book, he explores the history and meaning of such utopian communities for African Americans.
A professor who has devoted his career to resolving the mysteries of higher mathematics has solved two separate, fundamental problems that have perplexed mathematicians for decades.
For example, Propositional Dynamic Logic (PDL) can be described as a blend of three complementary classical ingredients: propositional calculus, modal logic, and the algebra of regular events ... and ...