context: It is highly unlikely that Mary left the football. It is probably not the case that John picked up the apple. It is almost certain that Julius is a frog. It is highly unlikely that if 'Mary left the football' or 'John picked up the apple' or both then Lily is a lion. Chances are about even that if 'John picked up the apple' or 'Mary left the football' or both then Sandra took the football. It is improbable that if 'John picked up the apple' or 'Julius is a frog' or both then Bernhard is green.
hypothesis: It is almost certain that 'Sandra took the football' or 'Julius is a frog' or both.
valid_hypothesis: It is almost certain that 'Sandra took the football' or 'Julius is a frog' or both.
invalid_hypothesis: It is highly unlikely that 'Sandra took the football' or 'Julius is a frog' 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
    0.05::factA.
    0.25::factB.
    0.95::factC.
    %hop1
    0.05::factX:-or(factA,factB).
    0.5::factY:-or(factB,factA).
    0.1::factZ:-or(factB,factC).
  
    %hop2
    conclusion:-or(factY,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Sandra took the football' or 'Julius is a frog' or both.