New generalizations of BCI, BCK and Hilbert algebras

We introduce more generalizations of BCI, BCK and of Hilbert algebras, with proper examples, and show the hierarchies existing between all these algebras, old and new ones. Namely, we found thirty one new generalizations of BCI and BCK algebras and twenty generalizations of Hilbert algebras.Comment: Open problems 11.3 (1), (2), (3) were solved. New (20'), (21''), Theorems 2.4,2.6, Cor. 2.5, 5.5 adde

Solid weak BCC-algebras

We characterize weak BCC-algebras in which the identity $(xy)z=(xz)y$ is satisfied only in the case when elements $x,y$ belong to the same branch