XIsabelle

XIsabelle [16] is another graphical interface to Isabelle, implemented in TCL/TK and Expect. One criticism of this interface is the complexity of the display presented to the user. An example screenshot in [16] contains no less than nine content panes visible. It should be possible to hide as many of these as desired by the user, in order to focus on particular areas. The inability to collapse and expand particular subgoals should be noted.