Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Minimum Connecting Transition Sets in Graphs   A forbidden transition graph is a graph defined together with a set of
permitted transitions i.e. unordered pair of adjacent edges that one may use
consecutively in a walk in the graph. In this paper, we look for the smallest
set of transitions needed to be able to go from any vertex of the given graph
to any other. We prove that this problem is NP-hard and study approximation
algorithms. We develop theoretical tools that help to study this problem.

18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas