the process
level, the parton level and the hadron level, and flags are grouped
accordingly. 

<h3>Process Level</h3>

The <code>ProcessLevel</code> class administrates the initial step of 
the event generation, wherein the basic process is selected. Currently 
this is done either using some of the internal processes, or with 
Les Houches Accord input.

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There could not be a complete event without an initial process, so
it would not be a normal action to switch off this step. Furthermore,
without a proc