In this paper, we analyze processes of conjecture generation in the context
of open problems proposed in a dynamic geometry environment, when a particular
dragging modality, maintaining dragging, is used. This involves dragging points
while maintaining certain properties, controlling the movement of the figures.
Our results suggest that the pragmatic need of physically controlling the
simultaneous movements of the different parts of figures can foster the
production of two chains of successive properties, hinged together by an
invariant that we will call pivot invariant. Moreover, we show how the
production of these chains is tied to the production of conjectures and to the
processes of argumentation through which they are generated.Comment: Research report at the 40th PME Conference, Hungar
