Implementing new geometric modelling operations can be challenging. However, their description can be easily understood from a sketch or an example. We propose a method to infer operations from a representative example consisting of an initial and a target object. The inference mechanism exploits the regularity of generalised maps and Jerboa’s rule-based language for the reconstruction of the topology. The inference of geometric aspects considers affine transformations of values from a vector space, which we solve as a constraint satisfaction problem.