context: Chances are about even that Mary discarded the milk. Chances are slight that Julius is a lion. There is little chance that Sandra is in the kitchen. It is highly likely that if 'Mary discarded the milk and Sandra is in the kitchen' then Emily is a sheep. It is almost certain that if 'Sandra is in the kitchen and Julius is a lion' then John moved to the office. Chances are about even that if 'Mary discarded the milk and Sandra is in the kitchen' then Brian is green.
hypothesis: Chances are about even that 'Mary discarded the milk' or 'John moved to the office' or both.
valid_hypothesis: Chances are about even that 'Mary discarded the milk' or 'John moved to the office' or both.
invalid_hypothesis: It is impossible that 'Mary discarded the milk' or 'John moved to the office' or 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
    0.5::factA.
    0.1::factB.
    0.1::factC.
    %hop1
    0.9::factX:-and(factA,factC).
    0.95::factY:-and(factC,factB).
    0.5::factZ:-and(factA,factC).
  
    %hop2
    conclusion:-or(factA,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary discarded the milk' or 'John moved to the office' or both.