There is almost no chance that Greg is yellow. We believe that Jessica is a mouse. It is almost certain that John discarded the apple. It is improbable that if either 'Greg is yellow' or 'John discarded the apple' but not both then Lily is a lion. It is impossible that if 'Greg is yellow' or 'John discarded the apple' or both then Julius is white. It is impossible that if 'Greg is yellow and John discarded the apple' then Mary went to the hallway.
We believe that 'Greg is yellow' or 'Jessica is a mouse' or both.
We believe that 'Greg is yellow' or 'Jessica is a mouse' or both.
We doubt that 'Greg is yellow' or 'Jessica is a mouse' or both.

  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
  0.02::factA.
  0.75::factB.
  0.95::factC.
  %hop1
  0.1::factX:-xor(factA,factC).
  0.0::factY:-or(factA,factC).
  0.0::factZ:-and(factA,factC).

  %hop2
  conclusion:-or(factA,factB).

  query(conclusion).
  
'Greg is yellow' or 'Jessica is a mouse' or both.