Influences of Three-Way Concept Lattice Caused by Variations of Attribute Values

Algorithm 2

Updating object-induced three-way concept lattice when changing a specific attribute value from 1 to 0.

	Require: and changing from 1 to 0.
	Ensure: .
(1)	Sort the concepts into a queue Q based on the ascending order of their extents.
(2)	For concept in Q
(3)	If there exists another concept such that , , and
(4)	Then
(5)	Generate a new concept .
(6)	If and , delete and .
(7)	If and , delete .
(8)	If and , delete .
(9)	End If
(10)	If and all the extents of its upper neighbours do not contain x
(11)	Then
(12)	If is a smallest father concept of such that
(13)	then generate a new concept .
(14)	End If
(15)	If and
(16)	Then
(17)	If there does not exist a concept , then generate a concept .
(18)	If there does not exist a concept , then generate a concept .
(19)	Delete .
(20)	End If
(21)	Update partial orders between concepts where necessary.
(22)	End For
(23)	Return the updated lattice and end the algorithm.