It is probably not the case that Gertrude is a cat. It is unlikely that John went to the bedroom. It is improbable that Mary moved to the garden. It is highly likely that if 'Gertrude is a cat' or 'John went to the bedroom' or both then Brian is a rhino. Chances are about even that if 'Gertrude is a cat' or 'Mary moved to the garden' or both then Julius is white. There is a very good chance that if 'Mary moved to the garden' or 'John went to the bedroom' or both then Lily is a lion.
It is highly unlikely that 'Brian is a rhino and Mary moved to the garden'.
It is highly unlikely that 'Brian is a rhino and Mary moved to the garden'.
It is highly likely that 'Brian is a rhino and Mary moved to the garden'.

  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
  0.25::factA.
  0.2::factB.
  0.1::factC.
  %hop1
  0.9::factX:-or(factA,factB).
  0.5::factY:-or(factA,factC).
  0.8::factZ:-or(factC,factB).

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

  query(conclusion).
  
'Brian is a rhino and Mary moved to the garden'.