context: It is almost certain that Emily is a wolf. It is improbable that Fred left the football. It is likely that Julius is white. It is probably not the case that if 'Emily is a wolf and Julius is white' then Mary went to the garden. It is highly likely that if 'Julius is white' or 'Fred left the football' or both then Sandra dropped the milk. We doubt that if either 'Julius is white' or 'Fred left the football' but not both then Greg is a rhino.
hypothesis: We believe that 'Sandra dropped the milk' or 'Julius is white' or both.
valid_hypothesis: We believe that 'Sandra dropped the milk' or 'Julius is white' or both.
invalid_hypothesis: It is improbable that 'Sandra dropped the milk' or 'Julius is white' 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
    0.95::factA.
    0.1::factB.
    0.7::factC.
    %hop1
    0.25::factX:-and(factA,factC).
    0.9::factY:-or(factC,factB).
    0.2::factZ:-xor(factC,factB).
  
    %hop2
    conclusion:-or(factY,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Sandra dropped the milk' or 'Julius is white' or both.