context: It is unlikely that Mary dropped the milk. Chances are slight that Jason is tired. We believe that Emily is a cat. It is probably the case that if 'Mary dropped the milk and Emily is a cat' then John got the milk. Chances are about even that if 'Jason is tired and Emily is a cat' then Brian is a lion. It is highly likely that if 'Mary dropped the milk' or 'Emily is a cat' or both then Sandra took the football.
hypothesis: Chances are slight that 'Emily is a cat and Jason is tired'.
valid_hypothesis: Chances are slight that 'Emily is a cat and Jason is tired'.
invalid_hypothesis: It is probable that 'Emily is a cat and Jason is tired'.
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
    0.2::factA.
    0.1::factB.
    0.75::factC.
    %hop1
    0.7::factX:-and(factA,factC).
    0.5::factY:-and(factB,factC).
    0.9::factZ:-or(factA,factC).
  
    %hop2
    conclusion:-and(factC,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Emily is a cat and Jason is tired'.