context: There is almost no chance that Mary went to the bedroom. It is almost certain that Julius is white. It is impossible that Bernhard is a frog. There is a very good chance that if either 'Julius is white' or 'Bernhard is a frog' but not both then John put down the milk. There is little chance that if either 'Mary went to the bedroom' or 'Bernhard is a frog' but not both then Greg is a rhino. We believe that if either 'Bernhard is a frog' or 'Mary went to the bedroom' but not both then Jessica is a sheep.
hypothesis: It is impossible that 'John put down the milk and Greg is a rhino'.
valid_hypothesis: It is impossible that 'John put down the milk and Greg is a rhino'.
invalid_hypothesis: It is almost certain that 'John put down the milk and Greg is a rhino'.
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
    0.02::factA.
    0.95::factB.
    0.0::factC.
    %hop1
    0.8::factX:-xor(factB,factC).
    0.1::factY:-xor(factA,factC).
    0.75::factZ:-xor(factC,factA).
  
    %hop2
    conclusion:-and(factX,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'John put down the milk and Greg is a rhino'.