context: It is probable that Brian is a frog. It is impossible that Jessica is a cat. It is highly unlikely that John took the apple. It is highly unlikely that if 'Jessica is a cat and Brian is a frog' then Julius is yellow. There is almost no chance that if either 'Brian is a frog' or 'John took the apple' but not both then Daniel got the milk. We doubt that if 'Jessica is a cat' or 'Brian is a frog' or both then Fred went to the office.
hypothesis: It is probably not the case that 'Brian is a frog' or 'John took the apple' or both.
valid_hypothesis: It is probable that 'Brian is a frog' or 'John took the apple' or both.
invalid_hypothesis: It is probably not the case that 'Brian is a frog' or 'John took 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
    0.7::factA.
    0.0::factB.
    0.05::factC.
    %hop1
    0.05::factX:-and(factB,factA).
    0.02::factY:-xor(factA,factC).
    0.2::factZ:-or(factB,factA).
  
    %hop2
    conclusion:-or(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Brian is a frog' or 'John took the apple' or both.