It is highly unlikely that Brian is a lion. Chances are slight that Bill went to the office. There is a better than even chance that Mary left the football. It is highly likely that if either 'Mary left the football' or 'Brian is a lion' but not both then Lily is a rhino. It is impossible that if 'Bill went to the office' or 'Brian is a lion' or both then John put down the apple. It is probably the case that if 'Mary left the football' or 'Brian is a lion' or both then Sandra dropped the milk.
It is improbable that 'Lily is a rhino' or 'Mary left the football' or both.
There is a better than even chance that 'Lily is a rhino' or 'Mary left the football' or both.
It is improbable that 'Lily is a rhino' or 'Mary left the football' 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
  0.05::factA.
  0.1::factB.
  0.6::factC.
  %hop1
  0.9::factX:-xor(factC,factA).
  0.0::factY:-or(factB,factA).
  0.7::factZ:-or(factC,factA).

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

  query(conclusion).
  
'Lily is a rhino' or 'Mary left the football' or both.