A. Paad - Department of Mathematics, University of Bojnord, Bojnord, Iran
A. Jafari - Department of Mathematics, University of Bojnord, Bojnord, Iran

In this paper, the notions of n-fold obstinate and n-fold fantastic (pre)filterin EQ-algebras are introduced and the relationship among n-fold obstinate, maximal, n-fold fantastic, and n-fold (positive) implicative prefilters are investigated. Moreover, the quotient EQ-algebra induced by an n-fold obstinate filter is studied and it is proved that the quotient EQ-algebra induced byan n-fold fantastic filter of a good EQ-algebra with bottom element ۰ is an involutive EQ-algebra. Finally, the relationships between types of n-fold filters in residuated EQ-algebras is shown by diagrams

EQ-algebra, n-fold obstinate (pre)filter, n-fold fantastic (pre)filter