It is improbable that Lily is a rhino. It is highly unlikely that Mary went to the office. It is highly likely that Julius is a swan. There is little chance that if 'Lily is a rhino and Julius is a swan' then Bernhard is a frog. It is impossible that if 'Mary went to the office and Lily is a rhino' then John put down the milk. We believe that if 'Lily is a rhino' or 'Mary went to the office' or both then Emily is a wolf.
It is certain that 'Lily is a rhino' or 'Emily is a wolf' or both.
There is little chance that 'Lily is a rhino' or 'Emily is a wolf' or both.
It is certain that 'Lily is a rhino' or 'Emily is a wolf' 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
  0.1::factA.
  0.05::factB.
  0.9::factC.
  %hop1
  0.1::factX:-and(factA,factC).
  0.0::factY:-and(factB,factA).
  0.75::factZ:-or(factA,factB).

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

  query(conclusion).
  
'Lily is a rhino' or 'Emily is a wolf' or both.