p Op
p we find a. But then we have ~a & a, which is an inconsistency. Hence ~Oa. Q.E.D.
Second proof by realism (AF): Since ~a and above lemma ~a
~Oa, hence ~Oa. Thus the axioms are not morally desirable either. Q.E.D. Note: q
p is equivalent to ~p
p Op
p we find a. But then we have ~a & a, which is an inconsistency. Hence ~Oa. Q.E.D.
Second proof by realism (AF): Since ~a and above lemma ~a
~Oa, hence ~Oa. Thus the axioms are not morally desirable either. Q.E.D. Note: q
p is equivalent to ~p