A non-empty subset S of a BCC-algebra
G is called a BCC-subalgebra of G, if xy ∈ S
whenever x,y ∈ S. If a binary relation ≤ on G is
defined by putting x ≤ y if and only if xy = 0, then
(G, ≤) is a partially ordered set. A non-empty subset
A of a BCC-algebra G is called a BCC-ideal, if
(5) 0 ∈ A,
(6) (xy)z ∈ A and y ∈ A imply xz ∈ A.
Putting z = 0 in (6) obtains: x ∈ y A and
y ∈ A implies x ∈A.
For more details, refer to Dudek (1992)
and Dudek and Zhang (1998).