imokay :- youreokay, hesokay. %C1
youreokay :- theyreokay. %C2
hesokay. %C3
theyreokay. %C4
?- imokay.







hesnotokay :- imnotokay. %C5
shesokay :- hesnotokay. %C6
shesokay :- theyreokay. %C7
?- shesokay.






hesnotokay :- shesokay. %C8
hesnotokay :- imokay. %C9
?- shesokay.

%facts
        scientist(sue). %1
        scientist(ron). %2
        spanish(sue).   %3
        american(ron).  %4
%rule
        logician(X) :- scientist(X). %5
%goal
        ?- logician(Y), american(Y).


(resolution)  R or P, (not P or Q)
              ____________________
                    R or Q


Truth table for ==>
  A\B true false
 true  t    f
false  t    t