1. A method to determine a complete parameter of a pulse sequence comprised of multiple pulse sequence modules, for operating a magnetic resonance apparatus, comprising: electronically storing parameter information of pulse sequence modules, that comprise a pulse sequence configured to operate a magnetic resonance apparatus, in leaves and nodes of a tree structure; and from a processor, accessing and retrieving the parameter information stored in said tree structure and, in said processor, executing a tree structure evaluation algorithm to determine a complete parameter of said pulse sequence.