Search an element in this set
(WARNING: frequent use of this method can cause a high overhead because usually it forces an internal partial decompression)
The SignedBPGraphReversalBlock class represents an elementary block of a signed permutation,
given by its start and end points, which can be used as the breakpoints of a signed reversal
The SignedPermutationBPGraph class represents a signed permutation pair
and its breakpoint graph
(the SignedPermutationBPGraph class does not deal with hurdles)