context: It is unlikely that Jeff went to the garden. It is certain that Mary put down the apple. It is probably the case that Lily is gray. There is little chance that if either 'Jeff went to the garden' or 'Lily is gray' but not both then Bernhard is a frog. It is unlikely that if 'Jeff went to the garden' or 'Mary put down the apple' or both then Sandra left the milk. There is a better than even chance that if 'Mary put down the apple' or 'Jeff went to the garden' or both then Greg is white.
hypothesis: It is almost certain that 'Jeff went to the garden and Sandra left the milk'.
valid_hypothesis: It is highly unlikely that 'Jeff went to the garden and Sandra left the milk'.
invalid_hypothesis: It is almost certain that 'Jeff went to the garden and Sandra left the milk'.
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.
    1.0::factB.
    0.7::factC.
    %hop1
    0.1::factX:-xor(factA,factC).
    0.2::factY:-or(factA,factB).
    0.6::factZ:-or(factB,factA).
  
    %hop2
    conclusion:-and(factA,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Jeff went to the garden and Sandra left the milk'.