Syntax: TOPO CREATE OVERLAY new_layer FROM old_layer1 {AND | OR | XOR | DIFF} old_layer2 [qualifiers]

Creates a new layer as the result of a topological overlay between two existing layers using one of the operators AND, OR, XOR or DIFF.

The type of the output layer is based on the input types:

The first column is the type of the first input layer. The first row is the type of the second input layer. The result of an overlay between these two types is shown in the other cells in this table. Notice that the order of the input layers is important in regard to the type of the output layer. For example, a POLYGON - POINT overlay results in a new POLYGON layer whereas a POINT - POLYGON overlay results in a new POINT layer.