context: It is probably the case that John picked up the apple. It is almost certain that Sandra took the football. It is impossible that Mary went to the office. There is a better than even chance that if 'Sandra took the football' or 'Mary went to the office' or both then Greg is yellow. It is improbable that if 'Sandra took the football and John picked up the apple' then Lily is a rhino. It is impossible that if 'Sandra took the football' or 'Mary went to the office' or both then Julius is a swan.
hypothesis: Chances are about even that 'John picked up the apple and Greg is yellow'.
valid_hypothesis: Chances are about even that 'John picked up the apple and Greg is yellow'.
invalid_hypothesis: It is impossible that 'John picked up the apple and Greg is yellow'.
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.
    0.95::factB.
    0.0::factC.
    %hop1
    0.6::factX:-or(factB,factC).
    0.1::factY:-and(factB,factA).
    0.0::factZ:-or(factB,factC).
  
    %hop2
    conclusion:-and(factA,factX).
  
    query(conclusion).
    
hypothesis_assertion: 'John picked up the apple and Greg is yellow'.