## Description part

After all signals are declared, you can begin the description part (see `pattern_begin` 3.9). In this part you have to define input values which are to be applied to the inputs of the circuit or output values which are to be compare with the values produced during the simulation. (see `affect` , `affect_any` 3.7, `affect_int` 3.5 and `affect_fix` 3.6). `Pattern` method describes the stimulus by event : only signal transitions are described. After each event there is a new input in the pattern file (see `addpat` 3.8). Last thing you should do in this part is to generate the output file (see `pattern_end` 3.10).