Murder

							 If the cook murdered Uncle Alfred
 then the weapon was poison.

 Either the cook murdered Uncle Alfred
 or the motive was revenge.

 The weapon was not poison.
                                         MODUS TOLLENS
 If the motive was revenge then
 the butler murdered Uncle Alfred.       If        then
The cook did not murder Uncle Alfred.
                                         Not

                                         Therefore not
 If the cook murdered Uncle Alfred
 then the weapon was poison.

 Either the cook murdered Uncle Alfred
 or the motive was revenge.

 The weapon was not poison.
                                         DISJUNCTIVE
 If the motive was revenge then          SYLLOGISM
 the butler murdered Uncle Alfred.
                                         Either      or
The cook did not murder Uncle Alfred.
                                         Not
 The motive was revenge.
                                         Therefore
 If the cook murdered Uncle Alfred
 then the weapon was poison.

 Either the cook murdered Uncle Alfred
 or the motive was revenge.

 The weapon was not poison.
                                         MODUS PONENS
 If the motive was revenge then
 the butler murdered Uncle Alfred.       If     then
The cook did not murder Uncle Alfred.

 The motive was revenge.
                                         Therefore

 The butler murdered Uncle Alfred
 If the cook murdered Uncle Alfred
 then the weapon was poison.
                                         JAI L
 Either the cook murdered Uncle Alfred
 or the motive was revenge.

 The weapon was not poison.

 If the motive was revenge then
 the butler murdered Uncle Alfred.

The cook did not murder Uncle Alfred.

 The motive was revenge.

 The butler murdered Uncle Alfred
 If the cook murdered Uncle Alfred
 then the weapon was poison.
                                         JAI L
 Either the cook murdered Uncle Alfred
 or the motive was revenge.

 The weapon was not poison.

 If the motive was revenge then
 the butler murdered Uncle Alfred.

The cook did not murder Uncle Alfred.

 The motive was revenge.

 The butler murdered Uncle Alfred