Title: Select expressions which contain variables
Goal: Generalize the function `f/1' by selecting the expressions `g(N), g(M)', the new parameter is `G'.
Parameters: [{file,"gen9.erl"},{posrange,{53,64}},{varname,"G"}].
Documentation: The selection contains variables (`N', `M'), so a new fun expression is created and added to every call of the function. The variables used in the selection becomes the parameters of the fun expression. There is not any variable with the name `G', so it is possible to introduce a new pattern and replace the expressions `g(N), g(M)' with an application. The name of the application is the new variable name and the arguments of the application are the used variables in the selected part.
