Hi, and welcome.
A couple of things before getting started. First, if applicable, see the homework policy and second, provide a reproducible example, called a reprex, so that a common data frame is available for answers and an illustration of an attempted solution.
The starting point is a class of problem within combinatorics. Let n = nrow(dataTOT). You are looking to create the set of combinations of n/2 objects taken 4 at a time from dataTOT, \binom{n/2}{4}.
For example, if n/2 = 10
m <- combn(10,4)
m
#> [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13] [,14]
#> [1,] 1 1 1 1 1 1 1 1 1 1 1 1 1 1
#> [2,] 2 2 2 2 2 2 2 2 2 2 2 2 2 2
#> [3,] 3 3 3 3 3 3 3 4 4 4 4 4 4 5
#> [4,] 4 5 6 7 8 9 10 5 6 7 8 9 10 6
#> [,15] [,16] [,17] [,18] [,19] [,20] [,21] [,22] [,23] [,24] [,25] [,26]
#> [1,] 1 1 1 1 1 1 1 1 1 1 1 1
#> [2,] 2 2 2 2 2 2 2 2 2 2 2 2
#> [3,] 5 5 5 5 6 6 6 6 7 7 7 8
#> [4,] 7 8 9 10 7 8 9 10 8 9 10 9
#> [,27] [,28] [,29] [,30] [,31] [,32] [,33] [,34] [,35] [,36] [,37] [,38]
#> [1,] 1 1 1 1 1 1 1 1 1 1 1 1
#> [2,] 2 2 3 3 3 3 3 3 3 3 3 3
#> [3,] 8 9 4 4 4 4 4 4 5 5 5 5
#> [4,] 10 10 5 6 7 8 9 10 6 7 8 9
#> [,39] [,40] [,41] [,42] [,43] [,44] [,45] [,46] [,47] [,48] [,49] [,50]
#> [1,] 1 1 1 1 1 1 1 1 1 1 1 1
#> [2,] 3 3 3 3 3 3 3 3 3 3 3 4
#> [3,] 5 6 6 6 6 7 7 7 8 8 9 5
#> [4,] 10 7 8 9 10 8 9 10 9 10 10 6
#> [,51] [,52] [,53] [,54] [,55] [,56] [,57] [,58] [,59] [,60] [,61] [,62]
#> [1,] 1 1 1 1 1 1 1 1 1 1 1 1
#> [2,] 4 4 4 4 4 4 4 4 4 4 4 4
#> [3,] 5 5 5 5 6 6 6 6 7 7 7 8
#> [4,] 7 8 9 10 7 8 9 10 8 9 10 9
#> [,63] [,64] [,65] [,66] [,67] [,68] [,69] [,70] [,71] [,72] [,73] [,74]
#> [1,] 1 1 1 1 1 1 1 1 1 1 1 1
#> [2,] 4 4 5 5 5 5 5 5 5 5 5 5
#> [3,] 8 9 6 6 6 6 7 7 7 8 8 9
#> [4,] 10 10 7 8 9 10 8 9 10 9 10 10
#> [,75] [,76] [,77] [,78] [,79] [,80] [,81] [,82] [,83] [,84] [,85] [,86]
#> [1,] 1 1 1 1 1 1 1 1 1 1 2 2
#> [2,] 6 6 6 6 6 6 7 7 7 8 3 3
#> [3,] 7 7 7 8 8 9 8 8 9 9 4 4
#> [4,] 8 9 10 9 10 10 9 10 10 10 5 6
#> [,87] [,88] [,89] [,90] [,91] [,92] [,93] [,94] [,95] [,96] [,97] [,98]
#> [1,] 2 2 2 2 2 2 2 2 2 2 2 2
#> [2,] 3 3 3 3 3 3 3 3 3 3 3 3
#> [3,] 4 4 4 4 5 5 5 5 5 6 6 6
#> [4,] 7 8 9 10 6 7 8 9 10 7 8 9
#> [,99] [,100] [,101] [,102] [,103] [,104] [,105] [,106] [,107] [,108]
#> [1,] 2 2 2 2 2 2 2 2 2 2
#> [2,] 3 3 3 3 3 3 3 4 4 4
#> [3,] 6 7 7 7 8 8 9 5 5 5
#> [4,] 10 8 9 10 9 10 10 6 7 8
#> [,109] [,110] [,111] [,112] [,113] [,114] [,115] [,116] [,117] [,118]
#> [1,] 2 2 2 2 2 2 2 2 2 2
#> [2,] 4 4 4 4 4 4 4 4 4 4
#> [3,] 5 5 6 6 6 6 7 7 7 8
#> [4,] 9 10 7 8 9 10 8 9 10 9
#> [,119] [,120] [,121] [,122] [,123] [,124] [,125] [,126] [,127] [,128]
#> [1,] 2 2 2 2 2 2 2 2 2 2
#> [2,] 4 4 5 5 5 5 5 5 5 5
#> [3,] 8 9 6 6 6 6 7 7 7 8
#> [4,] 10 10 7 8 9 10 8 9 10 9
#> [,129] [,130] [,131] [,132] [,133] [,134] [,135] [,136] [,137] [,138]
#> [1,] 2 2 2 2 2 2 2 2 2 2
#> [2,] 5 5 6 6 6 6 6 6 7 7
#> [3,] 8 9 7 7 7 8 8 9 8 8
#> [4,] 10 10 8 9 10 9 10 10 9 10
#> [,139] [,140] [,141] [,142] [,143] [,144] [,145] [,146] [,147] [,148]
#> [1,] 2 2 3 3 3 3 3 3 3 3
#> [2,] 7 8 4 4 4 4 4 4 4 4
#> [3,] 9 9 5 5 5 5 5 6 6 6
#> [4,] 10 10 6 7 8 9 10 7 8 9
#> [,149] [,150] [,151] [,152] [,153] [,154] [,155] [,156] [,157] [,158]
#> [1,] 3 3 3 3 3 3 3 3 3 3
#> [2,] 4 4 4 4 4 4 4 5 5 5
#> [3,] 6 7 7 7 8 8 9 6 6 6
#> [4,] 10 8 9 10 9 10 10 7 8 9
#> [,159] [,160] [,161] [,162] [,163] [,164] [,165] [,166] [,167] [,168]
#> [1,] 3 3 3 3 3 3 3 3 3 3
#> [2,] 5 5 5 5 5 5 5 6 6 6
#> [3,] 6 7 7 7 8 8 9 7 7 7
#> [4,] 10 8 9 10 9 10 10 8 9 10
#> [,169] [,170] [,171] [,172] [,173] [,174] [,175] [,176] [,177] [,178]
#> [1,] 3 3 3 3 3 3 3 4 4 4
#> [2,] 6 6 6 7 7 7 8 5 5 5
#> [3,] 8 8 9 8 8 9 9 6 6 6
#> [4,] 9 10 10 9 10 10 10 7 8 9
#> [,179] [,180] [,181] [,182] [,183] [,184] [,185] [,186] [,187] [,188]
#> [1,] 4 4 4 4 4 4 4 4 4 4
#> [2,] 5 5 5 5 5 5 5 6 6 6
#> [3,] 6 7 7 7 8 8 9 7 7 7
#> [4,] 10 8 9 10 9 10 10 8 9 10
#> [,189] [,190] [,191] [,192] [,193] [,194] [,195] [,196] [,197] [,198]
#> [1,] 4 4 4 4 4 4 4 5 5 5
#> [2,] 6 6 6 7 7 7 8 6 6 6
#> [3,] 8 8 9 8 8 9 9 7 7 7
#> [4,] 9 10 10 9 10 10 10 8 9 10
#> [,199] [,200] [,201] [,202] [,203] [,204] [,205] [,206] [,207] [,208]
#> [1,] 5 5 5 5 5 5 5 6 6 6
#> [2,] 6 6 6 7 7 7 8 7 7 7
#> [3,] 8 8 9 8 8 9 9 8 8 9
#> [4,] 9 10 10 9 10 10 10 9 10 10
#> [,209] [,210]
#> [1,] 6 7
#> [2,] 8 8
#> [3,] 9 9
#> [4,] 10 10
Created on 2019-12-15 by the reprex package (v0.3.0)
There are 210 possible combinations. Obviously as n increases, the number of combinations increases.
The second part of the problem is best addressed by linear algebra, using the matrix m produced by combn.
Let's take two pairs from m and test for similarity:
m <- combn(10,4)
m[,136] - m[,136] <= 1
#> [1] TRUE TRUE TRUE TRUE
m[,136] - m[,143] <= 1
#> [1] TRUE FALSE FALSE FALSE
Created on 2019-12-15 by the reprex package (v0.3.0)