running Bug2 causes error with SE2 object in Navigation.m

[fawills]

Executing Bug2.m with maps via bug = Bug2(maps) yields the following error:

Unrecognized function or variable 'SE2'.

Error in Navigation (line 145)
nav.w2g = SE2(0, 0, 0);

Error in Bug2 (line 78)
bug = bug@Navigation(varargin{:});

Tried SE2=stateSpaceSE2 at command line and re-ran Bug2.m with bug = Bug2(maps) at the command line. Got the same error.

SE2 is an object with the properties cited below:

SE2 =

stateSpaceSE2 with properties:

             Name: 'SE2'
      StateBounds: [3×2 double]
NumStateVariables: 3
         WeightXY: 1
      WeightTheta: 0.1000

SE2.StateBounds

ans =

-100.0000 100.0000
-100.0000 100.0000
-3.1416 3.1416

Any help or pointers is most appreciated