Vertical dot notation is not recognized

[c71n93]

For this example:

[x] > obj1
  [] > attr1
    x.plus 1 > @

[x] > obj2
  [] > attr2
    x.plus 2 > @

[x] > main
  attr1. > @
    x 1

AOI analysis doesn't produce any result. At the same time, for this example:

[x] > obj1
  [] > attr1
    x.plus 1 > @

[x] > obj2
  [] > attr2
    x.plus 2 > @

[x] > main
  (x 1).attr1 > @

AOI analysis produces the following correct result:

 <aoi>
    <obj fqn="main.x">
       <inferred>
          <obj fqn="obj1"/>
       </inferred>
    </obj>
 </aoi>

But these two examples are identical and should produce the same result. This means that tool can't recognize vertical dot notation. This should be fixed.