Some rephrasing.

diff --git a/README.txt b/README.txt
index a20e23d..afe5cb2 100644 (file)
--- a/README.txt
+++ b/README.txt
@@ -1,6 +1,6 @@
 
-                     Multi-Tracked Paths (MTP)
-                     -------------------------
+                       Multi-Tracked Paths (MTP)
+                       -------------------------
 
 * INTRODUCTION
 
@@ -56,7 +56,7 @@ that the procedure is similar to that of KSP, in the sense that the
 family it computes eventually is globally optimal, even if the
 computation is iterative.
 
-The MTPTracker is defined by
+The MTPTracker takes as input
 
  (1) a spatial topology composed of
 
@@ -76,24 +76,26 @@ The MTPTracker is defined by
              log( P(Y(l,t) = 1 | X) / P(Y(l,t) = 0 | X) )
 
      where Y is the occupancy of location l at time t and X is the
-     available observation.
+     available observation. Hence, this score is negative on locations
+     where the probability that the location is occupied is close to
+     0, and positive when it is close to 1.
 
-From this setting, MTPTracker has methods to compute the best set of
+From this parameters, an MTPTracker can compute the best set of
 disjoint trajectories consistent with the defined topology, which
 maximizes the overall detection score (i.e. the sum of the detection
-scores of the nodes visited by the trajectories). If no trajectory of
-total positive detection score exists, this optimal set of
-trajectories will be empty.
-
-The MTPTracker is a wrapper around the MTPGraph class. From the
-defined spatial topology and number of time steps, it builds a graph
-with one source, one sink, and two nodes per location and time. The
-edges from the source or to the sink, or between these pairs of nodes,
-are of length zero, and the edges between the two nodes of such a pair
-have negative lengths, equal to the opposite of the corresponding
-detection scores. This structure also ensures that the trajectories
-computed by the MTPTracker will be node-disjoint, since the
-trajectories computed by the MTPGraph are edge-disjoint.
+scores of the nodes visited by the trajectories). In particular, if no
+trajectory of total positive detection score exists, this optimal set
+of trajectories is empty.
+
+An MTPTracker is a wrapper around an MTPGraph. From the defined
+spatial topology and number of time steps, it builds a graph with one
+source, one sink, and two nodes per location and time. The edges from
+the source or to the sink, or between these pairs of nodes, are of
+length zero, and the edges between the two nodes of such a pair have
+negative lengths, equal to the opposite of the corresponding detection
+scores. This structure ensures that the trajectories computed by the
+MTPTracker will be node-disjoint, since the trajectories computed by
+the MTPGraph are edge-disjoint.
 
 The file mtp_example.cc gives a very simple usage example of the
 MTPTracker class by setting the tracker parameters dynamically, and