Ockham algebras with demi-pseudocomplementation

The variety dpK(1,1) consists of those algebras (L boolean AND, V, f*, 0, 1) of type (2, 2, 1, 1, 0, 0) where (L; boolean AND, V, f, 0, 1) is an Ockham algebra in which f(3) = f, (L; boolean AND, *, 0, 1) is a demi-pseudocomplemented lattice, and the unary operations f and * commute. Here we give a description of the structure of the lattice of congruences of a subdirectly irreducible algebra in dpK(1,1).