context: We doubt that Mary went to the garden. We believe that Brian is a rhino. It is unlikely that Bernhard is a lion. It is improbable that if 'Bernhard is a lion' or 'Mary went to the garden' or both then Lily is a swan. There is little chance that if either 'Bernhard is a lion' or 'Brian is a rhino' but not both then Gertrude is a cat. It is improbable that if 'Brian is a rhino' or 'Mary went to the garden' or both then John took the apple.
hypothesis: We believe that 'John took the apple' or 'Brian is a rhino' or both.
valid_hypothesis: We believe that 'John took the apple' or 'Brian is a rhino' or both.
invalid_hypothesis: It is probably not the case that 'John took the apple' or 'Brian is a rhino' 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
    0.2::factA.
    0.75::factB.
    0.2::factC.
    %hop1
    0.1::factX:-or(factC,factA).
    0.1::factY:-xor(factC,factB).
    0.1::factZ:-or(factB,factA).
  
    %hop2
    conclusion:-or(factZ,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'John took the apple' or 'Brian is a rhino' or both.