context: Chances are slight that John discarded the apple. There is a better than even chance that Emily is a mouse. There is a very good chance that Mary is in the hallway. It is highly likely that if either 'John discarded the apple' or 'Mary is in the hallway' but not both then Bill went to the kitchen. Chances are slight that if 'Emily is a mouse and Mary is in the hallway' then Julius is a frog. It is improbable that if 'Mary is in the hallway and Emily is a mouse' then Bernhard is white.
hypothesis: There is little chance that 'Emily is a mouse' or 'John discarded the apple' or both.
valid_hypothesis: There is a better than even chance that 'Emily is a mouse' or 'John discarded the apple' or both.
invalid_hypothesis: There is little chance that 'Emily is a mouse' or 'John discarded the apple' 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
    0.1::factA.
    0.6::factB.
    0.8::factC.
    %hop1
    0.9::factX:-xor(factA,factC).
    0.1::factY:-and(factB,factC).
    0.1::factZ:-and(factC,factB).
  
    %hop2
    conclusion:-or(factB,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Emily is a mouse' or 'John discarded the apple' or both.