my @points = ([1.0, 4.0],  [2.3, 0.7],  [3.6, 6.0],
              [4.0, 3.6]);
my @vertices=([0.0,  0.0], [0.5,  7.0], [2.0,  2.2],
              [2.2,  5.3], [4.6, -0.2], [5.2,  7.0]);
my @edges=( [0, 0, 1],   # Left bound for polygon on P0
            [1, 0, 2],   # P0 | P1
            [2, 1, 3],   # P0 | P2
            [3, 2, 3],   # P0 | P3
            [4, 0, 4],   # Lower bound for P1
            [5, 2, 4],   # P1 | P3
            [6, 3, 5],   # P2 | P3
            [7, 1, 5],   # Upper bound for P2
            [8, 4, 5] ); # Right bound for P3
my @lines=( [a, b, c, 0, -1],
            [a, b, c, 0,  1],
            [a, b, c, 0,  2],
            [a, b, c, 0,  3],
            [a, b, c, 1, -1],
            [a, b, c, 1,  3],
            [a, b, c, 2,  3],
            [a, b, c, 2, -1],
            [a, b, c, 3, -1]);

##</code><code>##

my @points = ([1.0, 4.0],
              [2.3, 0.7],
              [3.6, 6.0],
              [4.0, 3.6,  0]);  # Matches 0
my @edges=( [0, 0, 1],
            [1, 0, 2],
            [2, 1, 3],
            [3, 2, 3, 'removed'],
            [4, 0, 4],
            [5, 2, 4],
            [6, 3, 5],
            [7, 1, 5],
            [8, 4, 5] );
my @lines=( [a, b, c, 0, -1],
            [a, b, c, 0,  1],
            [a, b, c, 0,  2],
            [a, b, c, 0,  0, 3],  # removed! (same on both sides)
            [a, b, c, 1, -1],
            [a, b, c, 1,  0, 3],  # P3 replaced by P0
            [a, b, c, 2,  0, 3],  # P3 replaced by P0
            [a, b, c, 2, -1],
            [a, b, c, 0, -1]);
my @polygons=(
            [0, 1, 2, 5, 6, 8], # Poly 0 edges
            [1, 4, 5],          # Poly 1 edges
            [2, 6, 7] );        # Poly 2 edges