code: def isSegmentActive(self, seg, activeState):
      
      # Computing in C - *much* faster
      return isSegmentActive(seg.syns, activeState,
                             self.connectedPerm, self.activationThreshold)
docs: A segment is active if it has >= activationThreshold connected
      synapses that are active due to activeState.
  
      Notes: studied various cutoffs, none of which seem to be worthwhile
             list comprehension didn't help either