There is a better than even chance that Mary left the football. Chances are slight that Brian is white. It is almost certain that Jeff moved to the office. It is certain that if 'Mary left the football' or 'Jeff moved to the office' or both then Lily is yellow. Chances are slight that if 'Mary left the football' or 'Jeff moved to the office' or both then Greg is green. It is certain that if 'Brian is white and Mary left the football' then Julius is a frog.
It is impossible that 'Lily is yellow' or 'Greg is green' or both.
It is certain that 'Lily is yellow' or 'Greg is green' or both.
It is impossible that 'Lily is yellow' or 'Greg is green' 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
  0.6::factA.
  0.1::factB.
  0.95::factC.
  %hop1
  1.0::factX:-or(factA,factC).
  0.1::factY:-or(factA,factC).
  1.0::factZ:-and(factB,factA).

  %hop2
  conclusion:-or(factX,factY).

  query(conclusion).
  
'Lily is yellow' or 'Greg is green' or both.