Volume 2022, Issue 1 3238293
Research Article
Open Access

Fault Tolerant Partition Resolvability in Convex Polytopes

Asim Nadeem

Asim Nadeem

University of Management and Technology, Lahore, Pakistan umt.edu.pk

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Agha Kashif

Agha Kashif

Department of Mathematics, University of Management and Technology Lahore, Lahore, Pakistan

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Ebenezer Bonyah

Corresponding Author

Ebenezer Bonyah

Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development, Kumasi, Ghana

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Sohail Zafar

Sohail Zafar

University of Management and Technology, Lahore, Pakistan umt.edu.pk

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First published: 28 April 2022
Citations: 2
Academic Editor: Yong Aaron Tan

Abstract

Convex polytopes are special types of polytopes having an additional property that they are also convex sets in the n-dimensional Euclidean space. The convex polytope topologies are being used in the antitracking networks due to their stability, resilience, and destroy-resistance. The metric related parameters have been extensively studied in the recent times due to their applications in several areas including robot navigation, network designing, image processing, and chemistry. In this article, the sharp bounds for the fault tolerant partition dimension of certain well-known families of convex polytopes Rn, Qn, Sn, Tn, and Dn have been computed. Furthermore, we have studied the graphs having fault tolerant partition dimension bounded below by 4.

1. Introduction

The ability of a network to maintain its working capacity and functionality if one of its components fails to work is called fault tolerance. This guarantees the lower maintenance cost and longer durability of the network. Antitracking networks are used to protect users’ identities and communication confidentiality. A robust and resilient network topology is always required to ensure the strength and protection of antitracking network. Tian et al. [1], in their recent research, proposed the convex polytope topology in the antitracking network due to the stability, resilience, and destroy-resistance. The convex polytope topology can preserve the network stability, avoid the threat to key nodes and cut vertices, and achieve the self-optimization of network topology. Convex polytopes have been studied to a great extent for metric dimension and partition dimension. Imran et al. [2] computed the metric dimension of convex polytopes, whereas the bounds of fault tolerant metric dimension for some convex polytopes have been discussed in [3, 4]. Furthermore, fractional versions of metric related parameters for certain convex polytopes have been calculated in [5, 6].

Garey and Johnson in [7] concluded that computation of metric basis of a network is an NP-hard problem; it was further implied that computation of partition related metric parameters for general graphs is also NP-hard. This leads the current research trends to focus on the computation of these metric parameters for specific classes of graphs. In this regard, Liu et al. [8] and Chu et al. [9] recently computed sharp bounds of partition dimension for some families of convex polytopes. Following the same spirit, the fault tolerant partition dimension of certain convex polytopes is computed in the current work.

In a connected graph W, the node and edge sets of W are denoted by V(W) and E(W), respectively. The length of the shortest path connecting two nodes p and q is known as the distance between p and q denoted by d(p, q). For any node p of W and a nonempty subset A of V(W), the sets (HTML translation failed) and N(p) = {qV(G)|pqE(W)} are called the distance of a node p from subset A and the neighborhood of node p, respectively. Let Ω = {x1, x2, …, xl} be the set of ordered nodes; the representation of a node p with reference to Ω is a vector r(p|Ω) such that r(p|Ω) = (d(p, x1), d(p, x2), …, d(p, xl)). If the vectors r(p|Ω) are different, for every node of the graph, then Ω is termed as a resolving set of W. The minimal cardinality of Ω is termed as the metric dimension of W, represented by dim(W). Let Ψ = {B1, B2, …, Bl} be an ordered l−partition of a connected graph W. The representations of nodes with reference to Ψ are vectors r(p|ψ) such that r(p|ψ) = (d(p, B1), d(p, B2), …, d(p, Bl)). If vectors r(p|ψ) are different for every node of the graph, then l− partition is termed as a resolving partition of W. The minimal cardinality of a resolving partition Ψ is termed as the partition dimension of W, represented by p  d(W). The basic relationship between metric and partition dimension of graphs is given in [10].

Further study on partition dimension can be seen in [11, 12]. In 2015, Moreno et al. [13] presented the concept of κ− metric. If vectors r(p|Ω) are different in at least κ places for every node of the graph, then Ω is termed as a κ− metric generator for W. The κ− metric basis is a generator with least number of nodes. The minimal cardinality of Ω is termed as the κ− metric dimension of W, represented by dimκ(W). The 2-metric dimension was first presented in [14]. Further study on κ− metric dimension can be seen in [15, 16].

In 2020, Moreno et al. [17] presented the concept of κ− partition dimension of the graph. If vectors r(p|ψ) are different in at least κ places for every node of the graph, then Ψ is termed as a κ− partition generator of W. The κ− partition basis is a generator with least number of sets. The minimal cardinality of Ψ is termed as the κ− partition dimension of W, represented by pdκ(W). For κ = 2, the κ− partition dimension is known as fault tolerant partition dimension denoted by pd2(W). pd2(W) was computed for some important graphs in [18, 19] and further for circulant graphs in [20].

1.1. Main Results

The research conducted in this article leads to the subsequent results.

Theorem 1.

  • (1)

    For a graph W of order m ≥ 5 and having a vertex of degree at least 4, pd2(W) ≥ 4

  • (2)

    For n ≥ 5, 4 ≤ pd2(Rn) ≤ 5

  • (3)

    For n ≥ 6,

    • (a)

      4 ≤ pd2(Qn) ≤ 5

    • (b)

      4 ≤ pd2(Sn) ≤ 5

    • (c)

      4 ≤ pd2(Tn) ≤ 5

    • (d)

      3 ≤ pd2(Dn) ≤ 5

The rest of the article is organised in the following manner. In Section 2, the convex polytopes Rn, Qn, Sn, Tn, Dn are defined and lower and upper bounds of fault tolerant partition dimension for these infinite families of graphs are also computed. In Section 3, the article is concluded with a conjecture and an open problem.

2. Fault Tolerant Partition Dimension of Convex Polytopes

In this section, the bounds of fault partition dimensions of certain classes of convex polytopes Rn, Qn, Sn, Tn, Dn have been computed. In the following theorem, the graphs with fault tolerant partition dimension bounded below by 4 has been characterized.

Lemma 1. Let W be a graph of order m ≥ 5. If W has a node of degree at least 4, then pd2(W) ≥ 4.

Proof. Assume that pd2(W) = 3 for m ≥ 5. Let Λ = {B1, B2, B3} be a 2− partition basis of V(W). Let vk be the node of degree 4. Assume that vkB1. Let N(vk) = {x1, x2, x3, x4}.

  • Case 1: When |B1| = 1, the subcases are as follows:

  • Case 1.1: If each node of N(vk) is in either set B2 or B3, assuming that N(vk)⊆B2, then, for xN(vk), r(xi|Λ) = (1,0, bi), for 1 ≤ i ≤ 4, which results in a contradiction.

  • Now if N(vk)⊆B3, then, for xN(vk), r(xi|Λ) = (1, ai, 0), for 1 ≤ i ≤ 4, which again contradicts our assumption.

  • Case 1.2: Assume that B2 or B3 contains three nodes of N(vk).

  • Let xp, xq, xrN(vk)∩B2 and xtN(vk)∩B3; then r(vk|Λ) = (0,1,1), r(xq|Λ) = (1,0, b1), r(xq|Λ) = (1,0, b2), and r(xr|Λ) = (1,0, b3), which clearly leads to a contradictory situation. Meanwhile three nodes of N(vk) in B3 generate a similar case of contradiction.

  • Case 1.3: Assume that each of B2 and B3 contains two nodes from set N(vk). Let xp, xqN(vk)∩B2; then r(xp|Λ) = (1,0, b1) and r(xq|Λ) = (1,0, b2), which again results in a contradiction.

  • Case 2: When |B1| ≥ 2, the subcases are as follows:

  • Case 2.1: When |N(vk)∩B1| = 4, this implies that N(vk)⊆B1, and then r(vk|Λ) = (0, a0, b0) and, for xN(vk), r(xi|Λ) = (0, ai, bi), for 1 ≤ i ≤ 4. Hence, a0 − 1 ≤ a1, a2, a3, a4a0 + 1. Pigeonhole principle implies that at least two of nodes vk and xi are equidistant from B1 and B2, which results in a contradiction.

  • Case 2.2: When |N(vk)∩B1| = 3.

  • Let xp, xq, xrN(vk)∩B1 and xtN(vk)∩B2, and then r(vk|Λ) = (0,1, b0), r(xp|Λ) = (0, a1, b1), r(xq|Λ) = (0, a2, b2), and r(xr|Λ) = (0, a3, b3). In this situation, we get 1 ≤ a1, a2, a3 ≤ 2. Again Pigeonhole principle implies that at least two nodes among vk, xp, xq, and xr are equidistant from B1 and B2, which results in a contradiction. Meanwhile xtN(vk)∩B3 generates a similar case of contradiction.

  • Case 2.3: When |N(vk)∩B1| = 2.

  • Case 2.3.1: Let xp, xqN(vk)∩B1 and xr, xtN(vk)∩B2, and then r(vk|Λ) = (0,1, b0), r(xp|Λ) = (0, a1, b1), and r(xq|Λ) = (0, a2, b2). In this situation, we get 1 ≤ a1, a2 ≤ 2. Now the Pigeonhole principle implies that minimum two nodes among vk, xp, and xq are at the same distances from B1 and B2. This results in a contradiction. Meanwhile xr, xtN(vk)∩B3 generates a similar case of contradiction.

  • Case 2.3.2: Let xp, xqN(vk)∩B1, xrN(vk)∩B2, and xtN(vk)∩B3, and then r(vk|Λ) = (0,1,1), r(xp|Λ) = (0, a1, b1), and r(xq|Λ) = (0, a2, b2). In this situation, we get 1 ≤ a1, a2 ≤ 2. Now the Pigeonhole principle implies that the minimum two nodes among vk, xp, and xq are at the same distances from B1 and B2. This results in a contradiction.

  • Case 2.4: When |N(vk)∩B1| = 1.

  • Case 2.4.1: Let xpN(vk)∩B1 and xq, xr, xtN(vk)∩B2, and then r(vk|Λ) = (0,1, b0), r(xp|Λ) = (0, a1, b1), r(xq|Λ) = (1,0, b2), r(xr|Λ) = (1,0, b3), and r(xt|Λ) = (1,0, b4), which is a clear case of contradiction. Meanwhile xq, xr, xtN(vk)∩B3 generates a similar case of contradiction.

  • Case 2.4.2: Let xpN(vk)∩B1, xq, xrN(vk)∩B2, and xtN(vk)∩B3, and then r(vk|Λ) = (0,1,1), r(xp|Λ) = (0, a1, b1), r(xq|Λ) = (1,0, b2), r(xr|Λ) = (1,0, b3), and r(xt|Λ) = (1, a4, 0), which is again a clear case of contradiction. Meanwhile xq, xrN(vk)∩B3 and xtN(vk)∩B2 generates a similar case of contradiction.

  • Case 2.5: When |N(vk)∩B1| = 0. This case is similar to Case 1.

Hence, pd2(W) ≥ 4 for m ≥ 5 with (HTML translation failed) containing a node of degree at least 4.

2.1. Fault Tolerant Partition Dimension of Rn

In [21], Baca defined convex polytope Rn for n ≥ 5 with V(Rn) = {ui, vi, xi : 1 ≤ in} and E(Rn) = {uiui+1; ui, vi; ui+1vi; vivi+1; vixi; xixi+1 : 1 ≤ in}.

Conventionally, we assume that un+1 = u1, vn+1 = v1, and xn+1 = x1. The graph of convex polytope Rn is shown in Figure 1.

Details are in the caption following the image
Convex polytope Rn.

In the subsequent theorem, we compute the bounds of the fault tolerant partition dimension of convex polytope Rn.

Theorem 2. Consider convex polytope Rn with n ≥ 5; then 4 ≤ pd2(Rn) ≤ 5.

Proof. Let Ψ = {B1, B2, B3, B4, B5} be a partition of the node set V(Rn). We divide the proof in four parts and, in each part, it will be shown that Ψ is the fault tolerant partition generator for Rn. Let a = ⌊p/2⌋.

  • Case 1: For n = 4p.

  • Let B1 = {ui, vi : 1 ≤ in}, B2 = {xi : 1 ≤ ip}, B3 = {xi : p + 1 ≤ i ≤ 2p}, B4 = {xi : 2p + 1 ≤ i ≤ 3p}, and B5 = {xi : 3p + 1 ≤ i ≤ 3n}.

  • r(q|Ψ) are tabulated in Table 1.

  • Case 2: For n = 4p + 1.

  • Let B1 = {ui, vi : 1 ≤ in}, B2 = {xi : 1 ≤ ip + 1}, B3 = {xi : p + 2 ≤ i ≤ 2p + 1}, B4 = {xi : 2p + 2 ≤ i ≤ 3p + 1}, and B5 = {xi : 3p + 2 ≤ i ≤ 3n}.

  • r(q|Ψ) are tabulated in Table 2.

  • Case 3: For n = 4p + 2.

  • Let B1 = {ui, vi : 1 ≤ in}, B2 = {xi : 1 ≤ ip + 1}, B3 = {xi : p + 2 ≤ i ≤ 2p + 2}, B4 = {xi : 2p + 3 ≤ i ≤ 3p + 2}, and B5 = {xi : 3p + 3 ≤ i ≤ 3n}.

  • r(q|Ψ) are tabulated in Table 3.

  • Case 4: For n = 4p + 3.

  • Let B1 = {ui, vi : 1 ≤ in}, B2 = {xi : 1 ≤ ip + 1}, B3 = {xi : p + 2 ≤ i ≤ 2p + 2}, B4 = {xi : 2p + 3 ≤ i ≤ 3p + 3}, and B5 = {xi : 3p + 4 ≤ i ≤ 3n}.

  • r(q|Ψ) are tabulated in Table 4.

When p is odd, we have t = 2, whereas when p is even, t = 1 in the tables. Tables 14 clearly show that Ψ is the 2− resolving generator for Rn when n ≥ 5; therefore, pd2(Rn) ≤ 5 for n ≥ 5. Lemma 1 implies that pd2(Rn) ≥ 4 for n ≥ 5. This establishes our claim.

Table 1. r(q|Ψ) for Rn when n = 4p and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(1 ≤ ia + 1) 0 2 pi + 3 p + i + 1 i + 1
ui(a + 2 ≤ ip + 1) 0 2 pi + 3 2pi + 3 i + 1
ui(p + 2 ≤ ip + a + 1) 0 ip + 1 2 2pi + 3 i + 1
ui(p + a + 2 ≤ i ≤ 2p + 1) 0 ip + 1 2 2pi + 3 3pi + 3
ui(2p + 2 ≤ i ≤ 2p + a + 1) 0 ip + 1 i − 2p + 1 2 3pi + 3
ui(2p + a + 2 ≤ i ≤ 3p + 1) 0 ni + 3 i − 2p + 1 2 3pi + 3
ui(3p + 2 ≤ in − 2t + 1) 0 ni + 3 i − 2p + 1 in + p + 1 2
ui(n − 2t + 2 ≤ in) 0 ni + 3 5pi + 3 in + p + 1 2
vi(1 ≤ ia + t − 1) 0 1 pi + 2 p + i + 1 i + 1
vi(a + tip) 0 1 pi + 2 2pi + 2 i + 1
vi(p + 1 ≤ ip + a + t − 1) 0 ip + 1 1 2pi + 2 i + 1
vi(p + a + ti ≤ 2p) 0 ip + 1 1 2pi + 2 3pi + 2
vi(2p + 1 ≤ i ≤ 2p + a + t − 1) 0 ip + 1 i − 2p + 1 1 3pi + 2
vi(2p + a + ti ≤ 3p) 0 ni + 2 i − 2p + 1 1 3pi + 2
vi(3p + 1 ≤ ina) 0 ni + 2 i − 2p + 1 i − 3p + 1 1
vi(na + 1 ≤ in) 0 ni + 2 5pi + 2 i − 3p + 1 1
xi(1 ≤ ia + t − 1) 1 0 pi + 1 i + p i
xi(a + tip) 1 0 pi + 1 2pi + 1 i
xi(p + 1 ≤ ip + a + t − 1) 1 ip 0 2pi + 1 i
xi(p + a + ti ≤ 2p) 1 ip 0 2pi + 1 3pi + 1
xi(2p + 1 ≤ i ≤ 2p + a + t − 1) 1 ip i − 2p 0 3pi + 1
xi(2p + a + ti ≤ 3p) 1 ni + 1 i − 2p 0 3pi + 1
xi(3p + 1 ≤ ina) 1 ni + 1 i − 2p i − 3p 0
xi(na + 1 ≤ in) 1 ni + 1 5pi + 1 i − 3p 0
Table 2. Representations of nodes for Rn when n = 4p + 1 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(1 ≤ ia + 1) 0 2 pi + 4 p + i + 1 i + 1
ui(a + t + 1 ≤ ip + 2) 0 2 pi + 4 2pi + 4 i + 1
ui(p + 3 ≤ ip + a + t) 0 ip 2 2pi + 4 i + 1
ui(p + a + t + 1 ≤ i ≤ 2p + 2) 0 ip 2 2pi + 4 3pi + 4
ui(2p + 3 ≤ i ≤ 2p + a + 2) 0 ip i − 2p 2 3pi + 4
ui(2p + a + 3 ≤ i ≤ 3p + 2) 0 ni + 3 i − 2p 2 3pi + 4
ui(3p + 3 ≤ ina + 1) 0 ni + 3 i − 2p i − 3p 2
ui(na + 2 ≤ in) 0 ni + 3 5pi + 5 in + p + 1 2
vi(1 ≤ ia + 1) 0 1 pi + 3 p + i + 1 i + 1
vi(a + 2 ≤ i ≤ 2a + t) 0 1 pi + 3 2pi + 3 i + 1
vi(2a + t + 1 ≤ ip + a + 1) 0 ip 1 2pi + 3 i + 1
vi(p + a + 2 ≤ i ≤ 2p + 1) 0 ip 1 2pi + 3 3pi + 3
vi(2p + 2 ≤ i ≤ 2p + a + t) 0 ip i − 2p 1 3pi + 3
vi(2p + a + t + 1 ≤ i ≤ 3p + 1) 0 ni + 2 i − 2p 1 3pi + 3
vi(3p + 2 ≤ inat + 2) 0 ni + 2 i − 2p i − 3p 1
vi(nat + 3 ≤ in) 0 ni + 2 5pi + 4 i − 3p 1
xi(1 ≤ ia + 1) 1 0 pi + 2 i + p i
xi(a + 2 ≤ ip + 1) 1 0 pi + 2 2pi + 2 i
xi(p + 2 ≤ ip + a + 1) 1 ip − 1 0 2pi + 2 i
xi(p + a + 2 ≤ i ≤ 2p + 1) 1 ip − 1 0 2pi + 2 3pi + 2
xi(2p + 2 ≤ i ≤ 2p + a + 1) 1 ip − 1 i − 2p − 1 0 3pi + 2
xi(2p + a + 2 ≤ i ≤ 3p + 1) 1 ni + 1 i − 2p − 1 0 3pi + 2
xi(3p + 2 ≤ inat + 2) 1 ni + 1 i − 2p − 1 i − 3p − 1 0
xi(nat + 3 ≤ in) 1 ni + 1 5pi + 3 i − 3p − 1 0
Table 3. Representations of nodes for Rn when n = 4p + 2 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(1 ≤ ia + 2) 0 2 pi + 4 p + i + 1 i + 1
ui(a + 3 ≤ ip + 2) 0 2 pi + 4 2pi + 5 i + 1
ui(p + 3 ≤ ip + a + 2) 0 ip 2 2pi + 5 i + 1
ui(p + a + 3 ≤ i ≤ 2p + 3) 0 ip 2 2pi + 5 3pi + 5
ui(2p + 4 ≤ i ≤ 2p + a + t + 1) 0 ip i − 2p − 1 2 3pi + 5
ui(2p + a + t + 2 ≤ i ≤ 3p + 3) 0 ni + 3 i − 2p − 1 2 3pi + 5
ui(3p + 4 ≤ ina + 1) 0 ni + 3 i − 2p − 1 in + p + 1 2
ui(na + 2 ≤ in) 0 ni + 3 5pi + 6 in + p + 1 2
vi(1 ≤ ia + t) 0 1 pi + 3 p + i + 1 i + 1
vi(a + t + 1 ≤ ip + 1) 0 1 pi + 3 2pi + 4 i + 1
vi(p + 2 ≤ ip + a + t) 0 ip 1 2pi + 4 i + 1
vi(p + a + t + 1 ≤ i ≤ 2p + 2) 0 ip 1 2pi + 4 3pi + 4
vi(2p + 3 ≤ i ≤ 2p + a + 2) 0 ip i − 2p − 1 1 3pi + 4
vi(2p + a + 3 ≤ i ≤ 3p + 2) 0 ni + 2 i − 2p − 1 1 3pi + 4
vi(3p + 3 ≤ inat + 2) 0 ni + 2 i − 2p − 1 i − 3p − 1 1
vi(nat + 3 ≤ in) 0 ni + 2 5pi + 5 i − 3p − 1 1
xi(1 ≤ ia + t) 1 0 pi + 2 i + p i
xi(a + t + 1 ≤ ip + 1) 1 0 pi + 2 2pi + 3 i
xi(p + 2 ≤ ip + a + t) 1 ip − 1 0 2pi + 3 i
xi(p + a + t + 1 ≤ i ≤ 2p + 2) 1 ip − 1 0 2pi + 3 3pi + 3
xi(2p + 3 ≤ i ≤ 2p + a + 2) 1 ip − 1 i − 2p − 2 0 3pi + 3
xi(2p + a + 3 ≤ i ≤ 3p + 2) 1 4pi + 3 i − 2p − 2 0 3pi + 3
xi(3p + 3 ≤ inat + 2) 1 4pi + 3 i − 2p − 2 i − 3p − 2 0
xi(nat + 3 ≤ in) 1 4pi + 3 5pi + 4 i − 3p − 2 0
Table 4. Representations of nodes for Rn when n = 4p + 3 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(1 ≤ ia + 2) 0 2 pi + 4 p + i + 1 i + 1
ui(a + 3 ≤ ip + 2) 0 2 pi + 4 2pi + 5 i + 1
ui(p + 3 ≤ ip + a + t + 1) 0 ip 2 2pi + 5 i + 1
ui(p + a + t + 2 ≤ i ≤ 2p + 3) 0 ip 2 2pi + 5 3pi + 6
ui(2p + 4 ≤ i ≤ 2p + a + 3) 0 ip i − 2p − 1 2 3pi + 6
ui(2p + a + 4 ≤ i ≤ 3p + 4) 0 ni + 3 i − 2p − 1 2 3pi + 6
ui(3p + 5 ≤ inat + 2) 0 ni + 3 i − 2p − 1 i − 3p − 2 2
ui(nat + 3 ≤ in) 0 ni + 3 5pi + 7 in + p + 1 2
vi(1 ≤ ia + t) 0 1 pi + 3 p + i + 1 i + 1
vi(a + t + 1 ≤ ip + 1) 0 1 pi + 3 2pi + 4 i + 1
vi(p + 2 ≤ ip + a + 2) 0 ip 1 2pi + 4 i + 1
vi(p + a + 3 ≤ i ≤ 2p + 2) 0 ip 1 2pi + 4 3pi + 5
vi(2p + 3 ≤ i ≤ 2p + a + t + 1) 0 ip i − 2p − 1 1 3pi + 5
vi(2p + a + t + 2 ≤ i ≤ 3p + 3) 0 ni + 2 i − 2p − 1 1 3pi + 5
vi(3p + 4 ≤ ina) 0 ni + 2 i − 2p − 1 i − 3p − 2 1
vi(na + 1 ≤ in) 0 ni + 2 5pi + 6 i − 3p − 2 1
xi(1 ≤ ia + t) 1 0 pi + 2 i + p i
xi(a + t + 1 ≤ ip + 1) 1 0 pi + 2 2pi + 3 i
xi(p + 2 ≤ ip + a + 2) 1 ip − 1 0 2pi + 3 i
xi(p + a + 3 ≤ i ≤ 2p + 2) 1 ip − 1 0 2pi + 3 3pi + 4
xi(2p + 3 ≤ i ≤ 2p + a + t + 1) 1 ip − 1 i − 2p − 2 0 3pi + 4
xi(2p + a + t + 2 ≤ i ≤ 3p + 3) 1 ni + 1 i − 2p − 2 0 3pi + 4
xi(3p + 4 ≤ ina) 1 ni + 1 i − 2p − 2 i − 3p − 3 0
xi(na + 1 ≤ in) 1 ni + 1 5pi + 5 i − 3p − 3 0

2.2. Fault Tolerant Partition Dimension of Qn

In [22], Baca et al. defined convex polytope Qn for n ≥ 6 consisting of 3-sided, 4-sided, 5-sided, and n-sided faces, respectively. Here V(Qn) = {ui, vi, xi, yi : 1 ≤ in} and E(Qn) = {uiui+1; vivi+1; yiyi+1; uivi; vixi; vi+1xi; xiyi : 1 ≤ in}. Conventionally, we assume that un+1 = u1, vn+1 = v1, xn+1 = x1, and yn+1 = y1. The graph of convex polytope Qn is shown in Figure 2.

Details are in the caption following the image
Convex polytope Qn.

In the subsequent theorem, we compute the bounds of the fault tolerant partition dimension of convex polytope Qn.

Theorem 3. Consider convex polytope Qn with n ≥ 6; then 4 ≤ pd2(Qn) ≤ 5.

Proof. Let Ψ = {B1, B2, B3, B4, B5} be a partition of the node set V(Qn). We divide the proof in four parts and, in each part, it will be shown that Ψ is the fault tolerant partition generator for Qn. Let a = ⌊p/2⌋.

  • Case 1: For n = 4p.

  • Let B1 = {ui, vi, xi : 1 ≤ in}, B2 = {yi : 1 ≤ ip}, B3 = {yi : p + 1 ≤ i ≤ 2p}, B4 = {yi : 2p + 1 ≤ i ≤ 3p}, and B5 = {yi : 3p + 1 ≤ i ≤ 4n}.

  • r(q|Ψ) are tabulated in Table 5.

  • Case 2: For n = 4p + 1.

  • Let B1 = {ui, vi, xi : 1 ≤ in}, B2 = {yi : 1 ≤ ip + 1}, B3 = {yi : p + 2 ≤ i ≤ 2p + 1}, B4 = {yi : 2p + 2 ≤ i ≤ 3p + 1}, and B5 = {yi : 3p + 2 ≤ i ≤ 4n}.

  • r(q|Ψ) are tabulated in Table 6.

  • Case 3: For n = 4p + 2.

  • Let B1 = {ui, vi, xi : 1 ≤ in}, B2 = {yi : 1 ≤ ip + 1}, B3 = {yi : p + 2 ≤ i ≤ 2p + 2}, B4 = {yi : 2p + 3 ≤ i ≤ 3p + 2}, and B5 = {yi : 3p + 3 ≤ i ≤ 4n}.

  • r(q|Ψ) are tabulated in Table 7.

  • Case 4: For n = 4p + 3.

  • Let B1 = {ui, vi, xi : 1 ≤ in}, B2 = {yi : 1 ≤ ip + 1}, B3 = {yi : p + 2 ≤ i ≤ 2p + 2}, B4 = {yi : 2p + 3 ≤ i ≤ 3p + 3}, and B5 = {yi : 3p + 4 ≤ i ≤ 4n}.

  • r(q|Ψ) are tabulated in Table 8.

When p is odd, we have t = 2, whereas when p is even, t = 1 in the tables. Tables 58 clearly show that Ψ is the 2− resolving generator for Qn when n ≥ 6; therefore, pd2(Qn) ≤ 5 for n ≥ 6. Lemma 1 implies that pd2(Qn) ≥ 4 for n ≥ 6. This establishes our claim.

Table 5. r(q|Ψ) for Qn when n = 4p and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2)
ui(1 ≤ ia + 1) 0 3
ui(a + 2 ≤ ip + 1) 0 3
ui(p + 2 ≤ ip + a + 1) 0 ip + 2
ui(p + a + 2 ≤ i ≤ 2p + 1) 0 ip + 2
ui(2p + 2 ≤ i ≤ 2p + a + 1) 0 ip + 2
ui(2p + a + 2 ≤ i ≤ 3p + 1) 0 5pi − 3t + 3
ui(3p + 2 ≤ in − 2t + 1) 0 5pi − 3t + 3
ui(n − 2t + 2 ≤ in) 0 5pi − 3t + 3
vi(1 ≤ ia + 1) 0 2
vi(a + 2 ≤ ip + 1) 0 2
vi(p + 2 ≤ ip + a + 1) 0 ip + 1
vi(p + a + 2 ≤ i ≤ 2p + 1) 0 ip + 1
vi(2p + 2 ≤ i ≤ 2p + a + 1) 0 ip + 1
vi(2p + a + 2 ≤ i ≤ 3p + 1) 0 5pi − 3t + 2
vi(3p + 2 ≤ in − 2t + 1) 0 5pi − 3t + 2
vi(n − 2t + 2 ≤ in) 0 5pi − 3t + 2
xi(1 ≤ ia + t − 1) 0 1
xi(a + tip) 0 1
xi(p + 1 ≤ ip + a + t − 1) 0 ip + 1
xi(p + a + ti ≤ 2p) 0 ip + 1
xi(2p + 1 ≤ i ≤ 2p + a + t − 1) 0 ip + 1
xi(2p + a + ti ≤ 3p) 0 5pi − 3t + 1
xi(3p + 1 ≤ int − 1) 0 5pi − 3t + 1
xi(ntin) 0 5pi − 3t + 1
yi(1 ≤ ia + t − 1) 1 0
yi(a + tip) 1 0
yi(p + 1 ≤ ip + a + t − 1) 1 ip
yi(p + a + ti ≤ 2p) 1 ip
yi(2p + 1 ≤ i ≤ 2p + a + t − 1) 1 ip
yi(2p + a + ti ≤ 3p) 1 5pi − 3t
yi(3p + 1 ≤ int − 1) 1 5pi − 3t
yi(ntin) 1 5pi − 3t
Table 6. r(q|Ψ) for Qn when n = 4p + 1 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(1 ≤ ia + t) 0 3 pi + 5 p + i + 2 i + 2
ui(a + t + 1 ≤ ip + 2) 0 3 pi + 5 2pi + 5 i + 2
ui(p + 3 ≤ ip + a + t) 0 ip + 1 3 2pi + 5 i + 2
ui(p + a + t + 1 ≤ i ≤ 2p + 2) 0 ip + 1 3 2pi + 5 3pi + 5
ui(2p + 3 ≤ i ≤ 2p + a + 2) 0 ip + 1 i − 2p + 1 3 3pi + 5
ui(2p + a + 3 ≤ i ≤ 3p + 2) 0 5pi − 3t + 4 i − 2p + 1 3 3pi + 5
ui(3p + 3 ≤ int) 0 5pi − 3t + 4 i − 2p + 1 i − 3p + 1 3
ui(nt + 1 ≤ in) 0 5pi − 3t + 4 6pi − 3t + 5 i − 3p + 1 3
vi(1 ≤ ia + t) 0 2 pi + 4 p + i + 1 i + 1
vi(a + t + 1 ≤ ip + 2) 0 2 pi + 4 2pi + 4 i + 1
vi(p + 3 ≤ ip + a + t) 0 ip 2 2pi + 4 i + 1
vi(p + a + t + 1 ≤ i ≤ 2p + 2) 0 ip 2 2pi + 4 3pi + 4
vi(2p + 3 ≤ i ≤ 2p + a + 2) 0 ip i − 2p 2 3pi + 4
vi(2p + a + 3 ≤ i ≤ 3p + 2) 0 5pi − 3t + 3 i − 2p 2 3pi + 4
vi(3p + 3 ≤ int) 0 5pi − 3t + 3 i − 2p i − 3p 2
vi(nt + 1 ≤ in) 0 5pi − 3t + 3 6pi − 3t + 4 i − 3p 2
xi(1 ≤ ia + 1) 0 1 pi + 3 p + i + 1 i + 1
xi(a + 2 ≤ ip + 1) 0 1 pi + 3 2pi + 3 i + 1
xi(p + 2 ≤ ip + a + 1) 0 ip 1 2pi + 3 i + 1
xi(p + a + 2 ≤ i ≤ 2p + 1) 0 ip 1 2pi + 3 3pi + 3
xi(2p + 2 ≤ i ≤ 2p + a + t) 0 ip i − 2p 1 3pi + 3
xi(2p + a + t + 1 ≤ i ≤ 3p + 1) 0 5pi − 3t + 2 i − 2p 1 3pi + 3
xi(3p + 2 ≤ in − 2t + 1) 0 5pi − 3t + 2 i − 2p i − 3p 1
xi(n − 2t + 2 ≤ in) 0 5pi − 3t + 2 6pi − 3t + 3 i − 3p 1
yi(1 ≤ ia + 1) 1 0 pi + 2 p + i i
yi(a + 2 ≤ ip + 1) 1 0 pi + 2 2pi + 2 i
yi(p + 2 ≤ ip + a + 1) 1 ip − 1 0 2pi + 2 i
yi(p + a + 2 ≤ i ≤ 2p + 1) 1 ip − 1 0 2pi + 2 3pi + 2
yi(2p + 2 ≤ i ≤ 2p + a + t) 1 ip − 1 i − 2p − 1 0 3pi + 2
yi(2p + a + t + 1 ≤ i ≤ 3p + 1) 1 5pi − 3t + 1 i − 2p − 1 0 3pi + 2
yi(3p + 2 ≤ in − 2t + 1) 1 5pi − 3t + 1 i − 2p − 1 i − 3p − 1 0
yi(n − 2t + 2 ≤ in) 1 5pi − 3t + 1 6pi − 3t + 2 i − 3p − 1 0
Table 7. r(q|Ψ) for Qn when n = 4p + 2 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(1 ≤ ia + 2) 0 3 pi + 5 p + i + 2 i + 2
ui(a + 3 ≤ ip + 2) 0 3 pi + 5 2pi + 6 i + 2
ui(p + 3 ≤ ip + a + 2) 0 ip + 1 3 2pi + 6 i + 2
ui(p + a + 3 ≤ i ≤ 2p + a + 1) 0 ip + 1 3 2pi + 6 3pi + 6
ui(2p + a + 2 ≤ i ≤ 3p) 0 ip + 1 i − 2p 3 3pi + 6
ui(3p + 1 ≤ inat) 0 5pi + 2 i − 2p 3 3pi + 6
ui(nat + 1 ≤ in − 1) 0 5pit + 3 i − 2p i − 3p 3
ui(i = n) 0 5pit + 3 6pit + 4 i − 3p 3
vi(1 ≤ ia + 2) 0 2 pi + 4 p + i + 1 i + 1
vi(a + 3 ≤ ip + 2) 0 2 pi + 4 2pi + 5 i + 1
vi(p + 3 ≤ ip + a + 2) 0 ip 2 2pi + 5 i + 1
vi(p + a + 3 ≤ i ≤ 3pt) 0 ip 2 2pi + 5 3pi + 5
vi(3pt + 1 ≤ i ≤ 3p) 0 ip i − 2p − 1 2 3pi + 5
vi(3p + 1 ≤ inat) 0 5pit + 2 i − 2p − 1 2 3pi + 5
vi(nat + 1 ≤ in − 1) 0 5pit + 2 i − 2p − 1 i − 3p − 1 2
vi(i = n) 0 5pit + 2 6pit + 3 i − 3p − 1 2
xi(1 ≤ ia + t) 0 1 pi + 3 p + i + 1 i + 1
xi(a + t + 1 ≤ ip + 1) 0 1 pi + 3 2pi + 4 i + 1
xi(p + 2 ≤ ip + a + t) 0 ip 1 2pi + 4 i + 1
xi(p + a + t + 1 ≤ i ≤ 3pt − 1) 0 ip 1 2pi + 4 3pi + 4
xi(3pti ≤ 3pt + 1) 0 ip i − 2p − 1 1 3pi + 4
xi(3pt + 2 ≤ inat − 1) 0 5pit + 1 i − 2p − 1 1 3pi + 4
xi(natint) 0 5pit + 1 i − 2p − 1 i − 3p − 1 1
xi(nt + 1 ≤ in) 0 5pit + 1 6pit + 2 i − 3p − 1 1
yi(1 ≤ ia + t) 1 0 pi + 2 p + i i
yi(a + t + 1 ≤ ip + 1) 1 0 pi + 2 2pi + 3 i
yi(p + 2 ≤ ip + a + t) 1 ip − 1 0 2pi + 3 i
yi(p + a + t + 1 ≤ i ≤ 3pt − 1) 1 ip − 1 0 2pi + 3 3pi + 3
yi(3pti ≤ 3pt + 1) 1 ip − 1 i − 2p − 2 0 3pi + 3
yi(3pt + 2 ≤ inat − 1) 1 5pit i − 2p − 2 0 3pi + 3
yi(natint) 1 5pit i − 2p − 2 i − 3p − 2 0
yi(nt + 1 ≤ in) 1 5pit 6pit + 1 i − 3p − 2 0
Table 8. r(q|Ψ) for Qn when n = 4p + 3 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(1 ≤ ia + 2) 0 3 pi + 5 p + i + 2 i + 2
ui(a + 3 ≤ ip + 2) 0 3 pi + 5 2pi + 6 i + 2
ui(p + 3 ≤ ip + a + t + 1) 0 ip + 1 3 2pi + 6 i + 2
ui(p + a + t + 2 ≤ i ≤ 2p + at + 2) 0 ip + 1 3 2pi + 6 3pi + 7
ui(2p + at + 3 ≤ i ≤ 3p − 2t + 3) 0 ip + 1 i − 2p 3 3pi + 7
ui(3p − 2t + 4 ≤ in − 3t) 0 5pi − 3t + 6 i − 2p 3 3pi + 7
ui(n − 3t + 1 ≤ in − 2t + 1) 0 5pi − 3t + 6 i − 2p i − 3p − 1 3
ui(n − 2t + 2 ≤ in)ui(n − 2t + 2 ≤ in) 0 5pi − 3t + 6 6pi − 3t + 7 i − 3p − 1 3
vi(1 ≤ ia + 2) 0 2 pi + 4 p + i + 1 i + 1
vi(a + 3 ≤ ip + 2) 0 2 pi + 4 2pi + 5 i + 1
vi(p + 3 ≤ ip + a + t + 1) 0 ip 2 2pi + 5 i + 1
vi(p + a + t + 2 ≤ i ≤ 2p + 3) 0 ip 2 2pi + 5 3pi + 6
vi(2p + a + 4 ≤ i ≤ 3p + 4) 0 ip i − 2p − 1 2 3pi + 6
vi(2p + a + 4 ≤ i ≤ 3p + 4) 0 5pi − 3t + 5 i − 2p − 1 2 3pi + 6
vi(3p + 5 ≤ in − 2t + 1) 0 5pi − 3t + 5 i − 2p − 1 i − 3p − 2 2
vi(n − 2t + 2 ≤ in) 0 5pi − 3t + 5 6pi − 3t + 6 i − 3p − 2 2
xi(1 ≤ ia + t) 0 1 pi + 3 p + i + 1 i + 1
xi(a + t + 1 ≤ ip + 1) 0 1 pi + 3 2pi + 4 i + 1
xi(p + 2 ≤ ip + a + 2) 0 ip 1 2pi + 4 i + 1
xi(p + a + 3 ≤ i ≤ 2p + 2) 0 ip 1 2pi + 4 3pi + 5
xi(2p + 3 ≤ i ≤ 2p + a + t + 1) 0 ip i − 2p − 1 1 3pi + 5
xi(2p + a + t + 2 ≤ i ≤ 3p + 3) 0 5pi − 3t + 4 i − 2p − 1 1 3pi + 5
xi(3p + 4 ≤ int − 1) 0 5pi − 3t + 4 i − 2p − 1 i − 3p − 2 1
xi(ntin) 0 5pi − 3t + 4 6pi − 3t + 5 i − 3p − 2 1
yi(1 ≤ ia + t) 1 0 pi + 2 p + i i
yi(a + t + 1 ≤ ip + 1) 1 0 pi + 2 2pi + 3 i
yi(p + 2 ≤ ip + a + 2) 1 ip − 1 0 2pi + 3 i
yi(p + a + 3 ≤ i ≤ 2p + 2) 1 ip − 1 0 2pi + 3 3pi + 4
yi(2p + 3 ≤ i ≤ 2p + a + t + 1) 1 ip − 1 i − 2p − 2 0 3pi + 4
yi(2p + a + t + 2 ≤ i ≤ 3p + 3) 1 5pi − 3t + 3 i − 2p − 2 0 3pi + 4
yi(3p + 4 ≤ int − 1) 1 5pi − 3t + 3 i − 2p − 2 i − 3p − 3 0
yi(ntin) 1 5pi − 3t + 3 6pi − 3t + 4 i − 3p − 3 0

2.3. Fault Tolerant Partition Dimension of Sn

In [12], Imran et al. defined convex polytope Sn for n ≥ 6 consisting of 2n 3-sided faces, 2n 4-sided faces, and a pair of n-sided faces which can be constructed by combining convex polytope Rn with prism graph. Here V(Sn) = {ui, vi, xi, yi : 1 ≤ in} and E(Sn) = {uiui+1; vivi+1; xixi+1; yiyi+1; uj+1vi; ui, vi; vi, xi; xi, yi : 1 ≤ in}. Conventionally, we assume that un+1 = u1, vn+1 = v1, xn+1 = x1, and yn+1 = y1. The graph of convex polytope Sn is shown in Figure 3.

Details are in the caption following the image
Convex polytope Sn.

In the subsequent theorem, we compute the bounds of the fault tolerant partition dimension of convex polytope Sn.

Theorem 4. Consider convex polytope Sn with n ≥ 6; then 4 ≤ pd2(Sn) ≤ 5.

Proof. Let Ψ = {B1, B2, B3, B4, B5} be a partition of the node set V(Sn). The partition sets B1, B2, B3, B4, and B5 defined for convex polytope Qn are the same for Sn. Let a = ⌊p/2⌋. The representations of nodes ui, xi, and yi are the same in both Qn and Sn. The representations of nodes vi are shown in the tables below. When p is odd, we have t = 2 , whereas when p is even, t = 1 in the tables. Tables 912 clearly show that Ψ is the 2− resolving generator for Sn when n ≥ 6; therefore, pd2(Sn) ≤ 5 for n ≥ 5. Lemma 1 implies that pd2(Sn) ≥ 4 for n ≥ 6. This establishes our claim.

Table 9. r(q|Ψ) for Sn when n = 4p and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
vi(1 ≤ ia + t − 1) 0 2 pi + 3 p + i + 2 i + 2
vi(a + tip) 0 2 pi + 3 2pi + 3 i + 2
vi(p + 1 ≤ ip + a + t − 1) 0 ip + 2 2 2pi + 3 i + 2
vi(p + a + ti ≤ 2p) 0 ip + 2 2 2pi + 3 vi(p + a + ti ≤ 2p)
vi(2p + 1 ≤ i ≤ 2p + a + t − 1) 0 ip + 2 i − 2p + 2 2 3pi + 3
vi(2p + a + ti ≤ 3p) 0 5pi − 3t + 2 i − 2p + 2 2 3pi + 3
vi(3p + 1 ≤ int − 1) 0 5pi − 3t + 2 i − 2p + 2 i − 3p + 2 2
vi(ntin) 0 5pi − 3t + 2 6pi − 3t + 2 i − 3p + 2 2
Table 10. r(q|Ψ) for Sn when n = 4p + 1 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
vi(1 ≤ ia + 1) 0 2 pi + 4 p + i + 2 i + 2
vi(a + 2 ≤ ip + 1) 0 2 pi + 4 2pi + 4 i + 2
vi(p + 2 ≤ ip + a + 1) 0 ip + 1 2 2pi + 4 i + 2
vi(p + a + 2 ≤ i ≤ 2p + 1) 0 ip + 1 2 2pi + 4 3pi + 4
vi(2p + 2 ≤ i ≤ 2p + a + t) 0 ip + 1 i − 2p + 1 2 3pi + 4
vi(2p + a + t + 1 ≤ i ≤ 3p + 1) 0 5pi − 3t + 3 i − 2p + 1 2 3pi + 4
vi(3p + 2 ≤ in − 2t + 1) 0 5pi − 3t + 3 i − 2p + 1 i − 3p + 1 2
vi(n − 2t + 2 ≤ in) 0 5pi − 3t + 3 6pi − 3t + 4 i − 3p + 1 2
Table 11. r(q|Ψ) for Sn when n = 4p + 2 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
vi(1 ≤ ia + t) 0 2 pi + 4 p + i + 2 i + 2
vi(a + t + 1 ≤ ip + 1) 0 2 pi + 4 2pi + 5 i + 2
vi(p + 2 ≤ ip + a + t) 0 ip + 1 2 2pi + 5 i + 2
vi(p + a + t + 1 ≤ i ≤ 2p + 2) 0 ip + 1 2 2pi + 5 3pi + 5
vi(2p + 3 ≤ i ≤ 3p − 2t + 2) 0 ip + 1 i − 2p 2 3pi + 5
vi(3p − 2t + 3 ≤ ina − 2t) 0 5pi − 3t + 4 i − 2p 2 3pi + 5
vi(na − 2t + 1 ≤ in − 2t + 1) 0 5pi − 3t + 4 i − 2p i − 3p 2
vi(n − 2t + 2 ≤ in) 0 5pi − 3t + 4 6pi − 3t + 5 i − 3p 2
Table 12. r(q|Ψ) for Sn when n = 4p + 3 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
vi(1 ≤ ia + t) 0 2 pi + 4 p + i + 2 i + 2
vi(a + t + 1 ≤ ip + 1) 0 2 pi + 4 2pi + 5 i + 2
vi(p + 2 ≤ ip + a + 2) 0 ip + 1 2 2pi + 5 i + 2
vi(p + a + 3 ≤ i ≤ 2p + 2) 0 ip + 1 2 2pi + 5 3pi + 6
vi(2p + 3 ≤ i ≤ 3pt + 1) 0 ip + 1 i − 2p 2 3pi + 6
vi(3pt + 2 ≤ ina − 2t) 0 5pi − 3t + 5 i − 2p 2 3pi + 6
vi(na − 2t + 1 ≤ int − 1) 0 5pi − 3t + 5 i − 2p i − 3p − 1 2
vi(ntin) 0 5pi − 3t + 5 6pi − 3t + 5 i − 3p − 1 2

2.4. Fault Tolerant Partition Dimension of Tn

In [12], Imran et al. defined convex polytope Tn for n ≥ 6 consisting of 4n 3-sided faces, n 4-sided faces, and a pair of n-sided faces which can be constructed by combining convex polytope Rn with antiprism graph. Here V(Tn) = {ui, vi, xi, yi, 1 ≤ in} and E(Tn) = {uiui+1; uivi; ui+1vi; vivi+1; vi, xi; xi, xi+1; xiyi; xi+1yi; yiyi+1 : 1 ≤ in}. Conventionally, we assume that un+1 = u1, vn+1 = v1, xn+1 = x1, and yn+1 = y1. The graph of convex polytope Tn is shown in Figure 4.

Details are in the caption following the image
Convex polytope Tn.

In the subsequent theorem, we compute the bounds of the fault tolerant partition dimension of convex polytope Tn.

Theorem 5. Consider convex polytope Tn with n ≥ 6; then 4 ≤ pd2(Tn) ≤ 5.

Proof. Let Ψ = {B1, B2, B3, B4, B5} be a partition of the node set V(Tn). The partition sets B1, B2, B3, B4, and B5 defined for convex polytope Qn are the same for Tn. Let a = ⌊p/2⌋. The representations of nodes vi and yi are the same in both Qn and Tn. The representations of nodes ui and xi are shown in the tables below. When p is odd, we have t = 2, whereas when p is even, t = 1 in the tables. Tables 1316 clearly show that Ψ is the 2− resolving generator for Tn when n ≥ 6; therefore, pd2(Tn) ≤ 5 for n ≥ 6. Lemma 1 implies that pd2(Tn) ≥ 4 for n ≥ 6. This establishes our claim.

Table 13. r(q|Ψ) for Tn when n = 4p and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(i = 1) 0 3 pi + 4 p + i + 1 i + 2
ui(2 ≤ ipt) 0 3 pi + 4 p + i + 1 i + 1
ui(pt + 1 ≤ ip + 1) 0 3 pi + 4 2pi + 4 i + 1
ui(p + 2 ≤ i ≤ 2pt) 0 ip + 1 3 2pi + 4 i + 1
ui(2pt + 1 ≤ i ≤ 2p + 1) 0 ip + 1 3 2pi + 4 3pi + 4
ui(2p + 2 ≤ i ≤ 3pt) 0 ip + 1 i − 2p + 1 3 3pi + 4
ui(3pt + 1 ≤ in − 3t) 0 5pi − 3t + 3 i − 2p + 1 3 3pi + 4
ui(n − 3t + 1 ≤ int) 0 5pi − 3t + 3 i − 2p + 1 i − 3p + 1 3
ui(nt + 1 ≤ in) 0 5pi − 3t + 3 6pi − 3t + 3 i − 3p + 1 3
xi(1 ≤ ia + 1) 0 1 pi + 2 p + i i
xi(a + 2 ≤ ip + 1) 0 1 pi + 2 2pi + 2 i
xi(p + 2 ≤ ip + t + 2) 0 ip 1 2pi + 2 i
xi(p + t + 3 ≤ i ≤ 2p + 1) 0 ip 1 2pi + 2 3pi + 2
xi(2p + 2 ≤ i ≤ 3p − 2t + 1) 0 ip i − 2p 1 3pi + 2
xi(3p − 2t + 2 ≤ i ≤ 3p + 1) 0 5pi − 3t + 1 i − 2p 1 3pi + 2
xi(3p + 2 ≤ in − 2t + 1) 0 5pi − 3t + 1 i − 2p i − 3p 1
xi(n − 2t + 2 ≤ in) 0 5pi − 3t + 1 6pi − 3t + 1 i − 3p 1
Table 14. r(q|Ψ) for Tn when n = 4p + 1 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(i = 1) 0 3 pi + 5 p + i + 1 i + 2
ui(2 ≤ ip − 2t + 2) 0 3 pi + 5 p + i + 1 i + 1
ui(p − 2t + 3 ≤ ip + 2) 0 3 pi + 5 2pi + 5 i + 1
ui(p + 3 ≤ i ≤ 2p − 2t + 2) 0 ip 3 2pi + 5 i + 1
ui(2p − 2t + 3 ≤ i ≤ 2p + 2) 0 ip 3 2pi + 5 3pi + 5
ui(2p + 3 ≤ i ≤ 3pt + 1) 0 ip i − 2p 3 3pi + 5
ui(3pt + 2 ≤ in − 3t) 0 5pi − 3t + 4 i − 2p 3 3pi + 5
ui(n − 3t + 1 ≤ in − 2t + 1) 0 5pi − 3t + 4 i − 2p i − 3p 3
ui(n − 2t + 2 ≤ in) 0 5pi − 3t + 4 6pi − 3t + 5 i − 3p 3
xi(1 ≤ ia + t) 0 1 pi + 3 p + i i
xi(a + t + 1 ≤ ip + 2) 0 1 pi + 3 2pi + 3 i
xi(p + 3 ≤ ip + 2t + 1) 0 ip − 1 1 2pi + 3 i
xi(p + 2t + 2 ≤ i ≤ 2p + 2) 0 ip − 1 1 2pi + 3 3pi + 3
xi(2p + 3 ≤ i ≤ 3p − 2t + 2) 0 ip − 1 i − 2p − 1 1 3pi + 3
xi(3p − 2t + 3 ≤ i ≤ 3p + 2) 0 5pi − 3t + 2 i − 2p − 1 1 3pi + 3
xi(3p + 3 ≤ int) 0 5pi − 3t + 2 i − 2p − 1 i − 3p − 1 1
xi(nt + 1 ≤ in) 0 5pi − 3t + 2 6pi − 3t + 3 i − 3p − 1 1
Table 15. r(q|Ψ) for Tn when n = 4p + 2 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(i = 1) 0 3 pi + 5 p + i + 1 i + 2
ui(2 ≤ ipt + 1) 0 3 pi + 5 p + i + 1 i + 1
ui(pt + 2 ≤ ip + 2) 0 3 pi + 5 2pi + 6 i + 1
ui(p + 3 ≤ i ≤ 2pt + 1) 0 ip 3 2pi + 6 i + 1
ui(2pt + 2 ≤ i ≤ 2p + 3) 0 ip 3 2pi + 6 3pi + 6
ui(2p + 4 ≤ i ≤ 3p − 2t + 3) 0 ip i − 2p − 1 3 3pi + 6
ui(3p − 2t + 4 ≤ in − 3t) 0 5pi − 3t + 5 i − 2p − 1 3 3pi + 6
ui(n − 3t + 1 ≤ int) 0 5pi − 3t + 5 i − 2p − 1 i − 3p − 1 3
ui(nt + 1 ≤ in) 0 5pi − 3t + 5 6pi − 3t + 6 i − 3p − 1 3
xi(1 ≤ ia + 2) 0 1 pi + 3 p + i i
xi(a + 3 ≤ ip + 2) 0 1 pi + 3 2pi + 4 i
xi(p + 3 ≤ ip + t + 3) 0 ip − 1 1 2pi + 4 i
xi(p + t + 4 ≤ i ≤ 2p + 3) 0 ip − 1 1 2pi + 4 3pi + 4
xi(2p + 4 ≤ i ≤ 3pt + 1) 0 ip − 1 i − 2p − 2 1 3pi + 4
xi(3pt + 2 ≤ i ≤ 3p + 3) 0 5pi − 3t + 3 i − 2p − 2 1 3pi + 4
xi(3p + 4 ≤ int) 0 5pi − 3t + 3 i − 2p − 2 i − 3p − 2 1
xi(nt + 1 ≤ in) 0 5pi − 3t + 3 6pi − 3t + 4 i − 3p − 2 1
Table 16. r(q|Ψ) for Tn when n = 4p + 3 and a = ⌊p/2⌋.
Nodes d(q, B1) d(q, B2) d(q, B3) d(q, B4) d(q, B5)
ui(i = 1) 0 3 pi + 5 p + i + 1 i + 2
ui(2 ≤ ipt + 1) 0 3 pi + 5 p + i + 1 i + 1
ui(pt + 2 ≤ ip + 2) 0 3 pi + 5 2pi + 6 i + 1
ui(p + 3 ≤ i ≤ 2p − 2t + 3) 0 ip 3 2pi + 6 i + 1
ui(2p − 2t + 4 ≤ i ≤ 2p + 3) 0 ip 3 2pi + 6 3pi + 7
ui(2p + 4 ≤ i ≤ 3pt + 2) 0 ip i − 2p − 1 3 3pi + 7
ui(3pt + 3 ≤ in − 3t) 0 5pi − 3t + 6 i − 2p − 1 3 3pi + 7
ui(n − 3t + 1 ≤ int) 0 5pi − 3t + 6 i − 2p − 1 i − 3p − 2 3
ui(nt + 1 ≤ in) 0 5pi − 3t + 6 6pi − 3t + 7 i − 3p − 2 3
xi(1 ≤ ia + 2) 0 1 pi + 3 p + i i
xi(a + 3 ≤ ip + 2) 0 1 pi + 3 2pi + 4 i
xi(p + 3 ≤ ip + t + 2) 0 ip − 1 1 2pi + 4 i
xi(p + 2t + 3 ≤ i ≤ 2p + 3) 0 ip − 1 1 2pi + 4 3pi + 5
xi(2p + 4 ≤ i ≤ 3p − 2t + 3) 0 ip − 1 i − 2p − 2 1 3pi + 5
xi(3p − 2t + 4 ≤ i ≤ 3p + 4) 0 5pi − 3t + 4 i − 2p − 2 1 3pi + 5
xi(3p + 5 ≤ in − 2t + 1) 0 5pi − 3t + 4 i − 2p − 2 i − 3p − 2 1
xi(n − 2t + 2 ≤ in) 0 5pi − 3t + 4 6pi − 3t + 5 i − 3p − 2 1

2.5. Fault Tolerant Partition Dimension of Dn

In [4], Baca et al. defined convex polytope Dn for n ≥ 4 consisting of 2n5-sided faces. Here V(Dn) = {ui, vi, xi, yi : 1 ≤ in} and E(Dn) = {uiui+1; yiyi+1; uivi; vixi; vi+1xi; xiyi : 1 ≤ in}. Conventionally, we assume that un+1 = u1, xn+1 = v1, xn+1 = x1, and yn+1 = y1. The graph of convex polytope Dn is shown in Figure 5.

Details are in the caption following the image
Convex polytope Dn.

The following results in [6, 8] are important for us.

Proposition 1. Let G be a connected graph of order n; then

  • (1)

    p  d(G) = 2 if and only if G = Pn, where Pn is a path of order n ≥ 2;

  • (2)

    p  d(G) ≤ pd2(G).

In the subsequent theorem, we compute the bounds of the fault tolerant partition dimension of convex polytope Dn.

Theorem 6. Consider convex polytope Dn with n ≥ 6; then 3 ≤ pd2(Dn) ≤ 5.

Proof. Let ψ = {B1, B2, B3, B4, B5} be a partition of the node set V(Dn). The partition sets B1, B2, B3, B4, B5 defined for convex polytope Qn are the same for Dn. The representations of all the nodes are the same in both Qn and Dn. Hence, in view of Theorem 3 and Proposition 1, we have 3 ≤ pd2(Dn) ≤ 5 for n ≥ 6.

3. Conclusion

In this research article, we conclude that the fault tolerant partition dimension of the convex polytopes Rn, Qn, Sn, Tn, Dn is bounded above by 5. We also proved that the lower bound of fault tolerant partition dimension of all the families of graphs with order greater than or equal to 5 and having a node of degree at least 4 is 4 which includes first four of these convex polytopes. We conclude the article with a conjecture and an open problem.

Conjecture 1. The fault tolerant partition dimension of convex polytopes Rn, Qn, Sn, Tn, Dn is 5.

Open Problem 1. Compute the exact value of fault tolerant partition dimension of the convex polytopes Rn, Qn, Sn, Tn, Dn.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

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