Title: Select expressions which bind variable which are used outside the selection
Goal: Generalize the function `f/1' by selecting the expressions `g(N), M = N*2', the a new parameter is `F'.
Parameters: [{file,"gen12.erl"},{posrange,{43,57}},{varname,"F"}].
Documentation: The selection bind variable (`M') which are used outside the selected part in the expression (`g(M)'), after the transformation this variable would not be declared in the function body, so the refactoring refuse to perform this transformation.
