noOpportunity :: Exchange
noOpportunity = Exchange (Map.fromList d)
    where
      d = [((A,B), 2.0), ((B,A), 0.45)]
noOpportunity :: Exchange
noOpportunity = Exchange (Map.fromList d)
    where
      d = [((A,B), 2.0), ((B,A), 0.45)]
noOpportunity = Exchange (Map.fromList d)
    where
      d = [((A,B), 2.0), ((B,A), 0.45)]