context: It is probable that Sandra left the football. It is probable that Winona is a mouse. It is highly unlikely that John went to the garden. There is little chance that if 'John went to the garden and Winona is a mouse' then Julius is a lion. It is certain that if 'John went to the garden' or 'Sandra left the football' or both then Lily is gray. It is highly likely that if either 'Winona is a mouse' or 'Sandra left the football' but not both then Brian is a rhino.
hypothesis: It is highly unlikely that 'John went to the garden and Sandra left the football'.
valid_hypothesis: It is highly unlikely that 'John went to the garden and Sandra left the football'.
invalid_hypothesis: It is probably the case that 'John went to the garden and Sandra left the football'.
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.
    0.05::factC.
    %hop1
    0.1::factX:-and(factC,factB).
    1.0::factY:-or(factC,factA).
    0.9::factZ:-xor(factB,factA).
  
    %hop2
    conclusion:-and(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'John went to the garden and Sandra left the football'.