Volume 94: Sixteen papers on logic and algebra.- Some questions in the theory of algorithms 2.- A new algorithm for derivability in the constructive propositional calculus 3.- An associative calculus with an unsolvable problem of equivalence 4.- On the semantics of the theory of types 5.- On Horn formulas 6.- Generalized quasi-universal classes of models 7.- Some remarks on ultraproducts 8.- Conditions of decomposability of relations into direct products 9.- Partial universal algebras with prescribed lattices of subalgebras and correspondences 10.- On a class of mixed abelian groups with primary periodic part 11.- Completeness of holomorphs of abelian groups with automorphism 2 12.- An abstract characterization of the classes of semigroups of endomorphisms of systems of general type 13.- Strong bands of semigroups 14.- On lattice isomorphisms of commutative holoid semigroups 15.- Lattice isomorphisms of semigroups decomposable into free products 16.- On potential invertibility of elements of semigroups