It is probably the case that Gertrude is a cat. It is probably not the case that Bernhard is a rhino. There is little chance that John got the apple. There is almost no chance that if either 'John got the apple' or 'Bernhard is a rhino' but not both then Jessica is a cat. We doubt that if 'Gertrude is a cat' or 'John got the apple' or both then Sandra dropped the milk. It is highly unlikely that if either 'Gertrude is a cat' or 'Bernhard is a rhino' but not both then Mary moved to the office.
It is likely that 'Gertrude is a cat and John got the apple'.
It is highly unlikely that 'Gertrude is a cat and John got the apple'.
It is likely that 'Gertrude is a cat and John got the apple'.

  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
  0.7::factA.
  0.25::factB.
  0.1::factC.
  %hop1
  0.02::factX:-xor(factC,factB).
  0.2::factY:-or(factA,factC).
  0.05::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Gertrude is a cat and John got the apple'.