context: It is almost certain that Brian is yellow. It is highly unlikely that Mary went to the hallway. There is little chance that John picked up the apple. There is a very good chance that if 'John picked up the apple' or 'Mary went to the hallway' or both then Sandra got the football. It is probable that if 'Brian is yellow' or 'John picked up the apple' or both then Julius is a lion. It is almost certain that if 'Mary went to the hallway and Brian is yellow' then Bernhard is a swan.
hypothesis: It is likely that 'Sandra got the football' or 'Julius is a lion' or both.
valid_hypothesis: It is likely that 'Sandra got the football' or 'Julius is a lion' or both.
invalid_hypothesis: There is little chance that 'Sandra got the football' or 'Julius is a lion' 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.
    0.05::factB.
    0.1::factC.
    %hop1
    0.8::factX:-or(factC,factB).
    0.7::factY:-or(factA,factC).
    0.95::factZ:-and(factB,factA).
  
    %hop2
    conclusion:-or(factX,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Sandra got the football' or 'Julius is a lion' or both.