The concept of lacunary ideal convergence in intuitionistic fuzzy normed linear space (IFNLS) was introduced by the present author [P. Debnath, Lacunary ideal convergence in intuitionistic fuzzy normed linear spaces, Comput. Math. Appl., 63 (2012), 708-715]. In the current paper, the notion of lacunary difference ideal convergence (LDIC) has been introduced. Some previous results have been improved and extended in this new setting and some new results are incorporated as well. An open problem, discussed in the above mentioned paper, has also been solved here.The notion of lacunary ideal convergence in IFNLS was introduced by the author in [4]. In the present paper the author intends to improve and extend the results in [4] by introducing the concept of LDIC in IFNLS. Some new results are also introduced in this connection. In this article we give a solution to the future work mentioned in [4].Since an IFNLS is more general than a fuzzy normed linear space (FNLS), the results discussed in this paper are also valid for a FNLS.Throughout the paper N will denote the set of all natural numbers. First we collect some preliminary existing definitions in literature.
Definition 1.1. [18]The 5-tuple (X, µ, ν, * , •) is said to be an IFNLS if X is a linear space, * is a continuous t-norm, • is a continuous t-conorm, and µ, ν fuzzy sets on X × (0, ∞) satisfying the following conditions for every x, y ∈ X and s, t > 0:(a) µ(x, t) + ν(x, t) ≤ 1, (b) µ(x, t) > 0,