context: It is probable that Lily is a lion. It is probably the case that Sumit is thirsty. There is a very good chance that Bernhard is a swan. It is unlikely that if either 'Lily is a lion' or 'Sumit is thirsty' but not both then Emily is a sheep. There is little chance that if 'Bernhard is a swan and Lily is a lion' then Mary got the apple. It is probable that if 'Bernhard is a swan' or 'Sumit is thirsty' or both then Fred went to the garden.
hypothesis: It is highly unlikely that 'Sumit is thirsty and Bernhard is a swan'.
valid_hypothesis: There is a better than even chance that 'Sumit is thirsty and Bernhard is a swan'.
invalid_hypothesis: It is highly unlikely that 'Sumit is thirsty and Bernhard is a swan'.
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.
    0.7::factB.
    0.8::factC.
    %hop1
    0.2::factX:-xor(factA,factB).
    0.1::factY:-and(factC,factA).
    0.7::factZ:-or(factC,factB).
  
    %hop2
    conclusion:-and(factB,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Sumit is thirsty and Bernhard is a swan'.