In this thesis we firstly study a particular subclass of pseudocomplemented Ockham algebras (L;∧,∨, f,*, 0, 1) where (L;∧,∨, f, 0, 1) is an Ockham algebra, (L;∧,∨,*, 0, 1) is a p-algebra, and the operations x(?)f(x) and x(?)x* satisfy the identities f(x*) = x** and [f(x)]* = f2(x). We shall denote by bpO the class of these algebras. We show that if L∈bpO is subdirectly irreducible then Con L is a chain of the form:. Furthermore, we show that there are precisely eleven non-isomorphic subdirectly irreducible members in the class of these algebras and give a complete description of them.We also investigate the axioms in the variety eO of extended Ockham algebras. We extend Urquhart's theorem to eO-algebras and we are in particular concerned with the subclass e2M of eO-algebras in which f2 = id and k2 = id. We show that there are 19 non-equivalent axioms in e2M and then order them by implication.
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