context: It is probably the case that Antoine is thirsty. There is a better than even chance that John went to the office. It is highly unlikely that Brian is a rhino. Chances are slight that if 'Antoine is thirsty and Brian is a rhino' then Jeff moved to the garden. It is probably not the case that if 'Brian is a rhino and Antoine is thirsty' then Greg is yellow. Chances are slight that if 'Brian is a rhino and John went to the office' then Mary took the football.
hypothesis: Chances are slight that either 'Brian is a rhino' or 'Antoine is thirsty' but not both.
valid_hypothesis: It is likely that either 'Brian is a rhino' or 'Antoine is thirsty' but not both.
invalid_hypothesis: Chances are slight that either 'Brian is a rhino' or 'Antoine is thirsty' but not both.
problog: 
    and(A,B) :- A,B.
    or(A,B) :- A;B.
    nand(A,B) :- not(and(A,B)).
    nor(A,B) :- not(or(A,B)).
    xor(A,B) :- or(A,B), nand(A,B).
  
    %hop0
    0.7::factA.
    0.6::factB.
    0.05::factC.
    %hop1
    0.1::factX:-and(factA,factC).
    0.25::factY:-and(factC,factA).
    0.1::factZ:-and(factC,factB).
  
    %hop2
    conclusion:-xor(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Brian is a rhino' or 'Antoine is thirsty' but not both.