In this paper, we introduce the co-annihilator ⊥A of a set A and the co-annihilator of (F : a) of a relative to a prefilter (filter) F in an EQ-algebra ɛ. We investigate related properties of them, and obtain that the lattice of all prefilters
forms a pseudo-complemented lattice and the collection of all co-annihilators
forms a Boolean algebra in a separated EQ-algebra ɛ. Moreover, we introduce the notion of Δ-co-annihilators in an EQΔ-algebra ɛΔ and conclude that the collection of all Δ-prefilters
in an ℓEQΔ-algebra ɛΔ constitutes a relative pseudo-complemented lattice. Finally, we introduce and investigate two types of fuzzy co-annihilators Ann
R
(μ) and Ann (μ, ν) in ɛ. We come to a conclusion that the set of all fuzzy filters
in a residuated ℓEQ-algebra ɛ forms a relative pseudo-complemented lattice whence → is the Gödel residuated implication in St
r
(μ, ν).