Saeide Zahiri - Department of Mathematics, Faculty of Science, Higher Education Center of Eghlid, Eghlid, Iran
Arsham Borumand Saeid - Department of Pure Mathematics, Faculty of Mathematics and Computer, Shahid Bahonar University of Kerman, Kerman, Iran
Masoome Zahiri - Department of Mathematics, Faculty of Science, Higher Education Center of Eghlid, Eghlid, Iran

In this paper, we introduce the notion of co-annihilator of a subsetin a triangle algebra. It is shown that the co-annihilator of asubset is an interval valued residuated lattice (IVRL)-filter. Also, aspecial set of a triangle algebra is defined and the relationshipbetween this set and co-annihilator of a subset in triangle algebrais considered. Finally, co-annihilators preserving congruencerelation, or CP-congruence are defined and some results of themare given.

Triangle algebra, IVRL-filter, Co-annihilator, congruence