Chapter 1. Decidability vs. Undecidability of the Word Problem in Amalgams of Inverse Semigroups.- Chapter 2. A Nonfinitely Based Semigroup of Triangular Matrices.- Chapter 3. Regular Elements in Von Neumann Algebras.- Chapter 4. LeftRight Clifford Semigroups.- Chapter 5. Certain Categories Derived from Normal Categories.- Chapter 6. Semigroup Ideals and Permuting 3-derivations in Prime Near Rings.-...