# Finding position of a list in a nested list for which elements are equal

Suppose I have a nested list of the form:

test = {{1,2},{2,3},{1,6},{2,5},{2,2},{1,7},{1,4}}


How do I find the position of the list in which the elements are equal, which in this example is {5} -> position of {2,2}

Update 1

Suppose my nested list is:

{{0.99258878, 0.99258845}, {0.97357684, 0.97357712}, {0.95312105,
0.95386979}, {0.93345214, 0.93345301}, {0.91233411, 0.91233415}, {0.89050811,
0.89050798}, {0.86800801, 0.86800954}, {0.84486887, 0.84486964}, {0.82114124,
0.82114187}, {0.79689807, 0.79689753}}


I wish to find the position for which elements are equal with a 6 significant digit accuracy, like the position of the list {0.99258878, 0.99258845}

• Position[test, {a_, a_}]
– Syed
Mar 22, 2023 at 7:53
• @Syed thank you, suppose I have a very big nested list in which some elements are approximately equal, say a list like {1.5,1.4999} or {1.88812,1.88913} how to include the positions of these as well? How to state the level of accuracy? Mar 22, 2023 at 7:58
• Please update the post and present a list with real numbers and the accuracy required. This is new information.
– Syed
Mar 22, 2023 at 8:01
• @Syed I have updated my question! Mar 22, 2023 at 8:20
• A variation on the method given below by Syed: Round[lst,10^-6]//MapApply[Subtract]//Position[0] Mar 23, 2023 at 18:39

Using Round with the second argument:
test = {{0.99258878, 0.99258845}, {0.97357684,