context: It is likely that Mary left the football. It is probable that Julius is a lion. There is a very good chance that John picked up the apple. There is a better than even chance that if 'John picked up the apple and Julius is a lion' then Bernhard is gray. Chances are slight that if either 'Julius is a lion' or 'John picked up the apple' but not both then Winona is a wolf. It is highly likely that if 'Mary left the football' or 'John picked up the apple' or both then Jason is tired.
hypothesis: We doubt that 'Mary left the football' or 'Jason is tired' or both.
valid_hypothesis: It is highly likely that 'Mary left the football' or 'Jason is tired' or both.
invalid_hypothesis: We doubt that 'Mary left the football' or 'Jason is tired' 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.
    0.8::factC.
    %hop1
    0.6::factX:-and(factC,factB).
    0.1::factY:-xor(factB,factC).
    0.9::factZ:-or(factA,factC).
  
    %hop2
    conclusion:-or(factA,factZ).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary left the football' or 'Jason is tired' or both.