Table 1 Edits to geometries and their associated change scripts. Ids 1–3 are modification, creation, and deletion of a point, id = 4 is modification of a linestring by inserting, modifying, and deleting vertices. Id =5 is modification of a polygon by modifying one vertex in the shell and deleting the hull. Geometries are described using the WKT format

1

Point

(10.53 60.10)

(10.52 60.10)

Modify, (-0.01 0)

2

Point

Null

(10.53 60.10)

Create, (10.53 60.10)

3

Point

(10.53 60.10)

Null

Delete, (10.53 60.10)

4

LineString

(1 1, 2 2, 3 3, 4 4)

(0 0, 1 1, 2.5 2.5, 3 3)

{0: Insert, (0 0), 1: Modify, (0.5 0.5) 3: Delete, (4 4)}

5

Polygon

((0 0, 10 0, 5 10, 0 0), (1 1, 2 2, 2 1, 1 1))

((0 0, 10 0, 6 10, 0 0))

{0: Modify, {2: (1, 0)}, 1: Delete, (1 1, 2 2, 2 1, 1 1)}