Theorem 3.3. Let θ ∈ pCon(X). Then C1 = {x ∈ X : x ∼θ 1} is a pseudo filter of
X.
Proof. Since θ is a reflexive relation, we see that (1, 1) ∈ θ and so 1 ∼θ 1. Thus
1 ∈ C1. Now, let x, y ∈ X. Assume that a ∈ C1, a ∗ x ∈ C1. Then a ∗ x ∼θ 1. Now,
we have x ⋄ (a ∗ x) ∼θ x ⋄ 1. Thus 1 ∼θ a ∼θ x and so x ∈ C1. This shows that C1 is
a pseudo filter of X.