It is highly likely that Lily is a rhino. Chances are about even that Brian is a swan. Chances are slight that Greg is gray. It is highly likely that if 'Greg is gray' or 'Lily is a rhino' or both then Jason is tired. Chances are about even that if 'Lily is a rhino and Greg is gray' then Mary took the football. It is unlikely that if 'Greg is gray' or 'Brian is a swan' or both then John moved to the office.
Chances are slight that 'John moved to the office' or 'Lily is a rhino' or both.
It is highly likely that 'John moved to the office' or 'Lily is a rhino' or both.
Chances are slight that 'John moved to the office' or 'Lily is a rhino' 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
  0.9::factA.
  0.5::factB.
  0.1::factC.
  %hop1
  0.9::factX:-or(factC,factA).
  0.5::factY:-and(factA,factC).
  0.2::factZ:-or(factC,factB).

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

  query(conclusion).
  
'John moved to the office' or 'Lily is a rhino' or both.