The ActiveMath learning environment is based on semantic mathematical formulae encoded using OpenMath1 . This gives it a chance to render formulae on a variety of platforms, using cultural-dependent adap- tations, and with added-value services that may help the learners in read- ing the formulae. The price to pay at authoring, however, is high since it requires encoding the meaning and not only the graphical presentation of the formulae. Examples of challenges include the input of K[x1 , ..., xn ] which is well known to represent the ring of polynomials on n variables but which does not enjoy, yet, the support of official Content Dictionaries for the symbols. In this paper, we explain methods we propose to discover the symbols needed to encode expressions, the typical expressions, and the ways to input this within the ActiveMath learning environment with jEditOQMath and to have it rendered. En passant, we describe requirements on the browsing and search methods for the presentations of OpenMath Content Dictionaries.