Dealing with Contradictory Mental Attitudes

• Whenever there is a contradiction in the various mental attitudes (e.g., achievable vs. unachievable or intention vs. not an intention) ALFA rules in favor of the attitude that it attains later (recency prejudice [Per97]) using the contradiction handling rules (6.30) and (6.31). An indiscriminate application of recency prejudice to deal with all contradictions in an agent's KB may not be appropriate and in many cases wrong [Per97]. However, when dealing with an agent's mental attitudes like desires, intentions, expectations, observations and achievements, recency prejudice seems reasonable. Therefore, (6.30) and (6.31) apply recency prejudice only to mental attitudes other than beliefs.

  $$\begin{split}& \ntt(N_1,T_1) \wedge \ntt(N_2, T_2) \wedge \\ ... ...\_,\_)) \\ & \qquad \looparrowright \reinstate(N_1) \end{split}$$ (60)

  
  

  $$\begin{split}& \ntt(N_1,T_1) \wedge \ntt(N_2, T_2) \wedge \\ ... ...\_,\_)) \\ & \qquad \looparrowright \reinstate(N_2) \end{split}$$ (61)