It is almost certain that Gertrude is a mouse. It is probably the case that Julius is a rhino. It is likely that John got the apple. It is impossible that if either 'Julius is a rhino' or 'John got the apple' but not both then Lily is a swan. It is certain that if either 'Julius is a rhino' or 'John got the apple' but not both then Bernhard is a lion. Chances are about even that if 'Gertrude is a mouse and Julius is a rhino' then Mary went to the garden.
We doubt that 'Julius is a rhino' or 'Mary went to the garden' or both.
It is probably the case that 'Julius is a rhino' or 'Mary went to the garden' or both.
We doubt that 'Julius is a rhino' or 'Mary went to the garden' 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
  0.95::factA.
  0.7::factB.
  0.7::factC.
  %hop1
  0.0::factX:-xor(factB,factC).
  1.0::factY:-xor(factB,factC).
  0.5::factZ:-and(factA,factB).

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

  query(conclusion).
  
'Julius is a rhino' or 'Mary went to the garden' or both.