context: It is probably the case that Jeff dropped the apple. It is probably the case that Jessica is a sheep. It is highly unlikely that Bernhard is a rhino. It is probably the case that if 'Jessica is a sheep and Bernhard is a rhino' then Fred went to the garden. There is almost no chance that if 'Jeff dropped the apple and Bernhard is a rhino' then Emily is a mouse. There is little chance that if 'Jessica is a sheep' or 'Jeff dropped the apple' or both then Brian is a swan.
hypothesis: It is unlikely that 'Jessica is a sheep' or 'Fred went to the garden' or both.
valid_hypothesis: It is probable that 'Jessica is a sheep' or 'Fred went to the garden' or both.
invalid_hypothesis: It is unlikely that 'Jessica is a sheep' or 'Fred went to the garden' 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
    0.7::factA.
    0.7::factB.
    0.05::factC.
    %hop1
    0.7::factX:-and(factB,factC).
    0.02::factY:-and(factA,factC).
    0.1::factZ:-or(factB,factA).
  
    %hop2
    conclusion:-or(factB,factX).
  
    query(conclusion).
    
hypothesis_assertion: 'Jessica is a sheep' or 'Fred went to the garden' or both.