and string_expr () = function
| EGoalDefn (loc, goal) -> string_goal () (None, goal)
| EFuncDefn (loc, func) -> string_func () (None, func)
and string_expr () = function
| EGoalDefn (loc, goal) -> string_goal () (None, goal)
| EFuncDefn (loc, func) -> string_func () (None, func)