The input automaton is a classical automaton. Stamina will compute its star height.
It first finds an upper bound using the Loop Complexity heuristics, and then proceeds with the star height computation.
************LOOP COMPLEXITY******************
According to the Loop Complexity heuristics, the star-height is at most 1.
A regular expression for the language (omitting epsilon) is: ((ab+aabb)+(ab+aabb)((ab+aabb))*(ab+aabb))
The Loop Complexity suggests the following unboundedness witness: ab(ab)^#ab
************STAR HEIGHT COMPUTATION**********
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Testing star height 0
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RESULTS: the star height is 1, as predicted by the Loop Complexity heuristics, and a regular expression witnessing it is ((ab+aabb)+(ab+aabb)((ab+aabb))*(ab+aabb)).