Adding connectives To add a new connective press the "connective" button on the main control panel. A new window should pop up labelled "xmagic: connectives". First type in a symbol for your new connective in the "symbol:" dialog box. Press the "accept" button under the box. The second dialog box labelled "define connective" should now become active. Also you should see your symbol appearing to the left of the box. Now you should select whether you want your connective to be a constant, a unary connective (i.e., acting on one argument only) or a binary connective (i.e., acting on two argu- ments). Your choice will be reflected by a different string appearing to the left of the "define connective" box. That string also shows the letters you should use for the argu- ments of the connective. You should use "a" as an argument of a unary connective, and "a" and "b" as arguments of the binary connective. You can now type in a corresponding formula. To send the formula to MaGIC press the second "accept" button located under the "define connective:" dialog box. If MaGIC accepts your formula the newly defined connective will be placed in the list of defined connectives under the dialog boxes. You cannot delete a connective once it has been defined. When the "defined connectives:" table becomes full both dialog boxes in the upper part of the connectives win- dow will become insensitive. You can define up to 6 new con- nectives at a time. Pressing the "reset all" button on the main control panel will undefine all connectives and you will be able to start the definitions from the beginning.