1. A method to be executed at least in part in a computing device for inferring diagram structure through implicit shape relationships, the method comprising: determining a logic structure of a plurality of shapes on a diagram canvas; receiving an action associated with at least one of the plurality of shapes; determining a relationship between the at least one of the plurality of shapes and other shapes within the logic structure; determining effects of the received action on the at least one of the plurality of shapes and the other shapes; and applying the effects to the at least one of the plurality of shapes and the other shapes.