For more information about one-to-one mappings see One-to-one mapping and Transforms that create one-to-one mappings.
To create a new one-to-one mapping:
The mapping editor creates a new mapping between the source element and the target element, consisting of: (a) a new transform; (b) a connection from the source element to the transform; and (c) a connection from the transform to the target element.
The type of the new transform is set to an appropriate default transform type (see Default transform type).
You can also use the contextual menu to create a one-to-one mapping:
In the mapping routine area, right-click the source element.
Select Create Connection. The mapping editor displays a wire that is anchored to the source element on the left side but that is unanchored on the right side.
Click the target element.
The mapping editor creates the new mapping in the same way that it does when you drag the source element to the target element.