There is a better than even chance that John got the apple. There is a very good chance that Lily is a lion. It is unlikely that Gertrude is a cat. There is a very good chance that if either 'Lily is a lion' or 'John got the apple' but not both then Jessica is a mouse. It is impossible that if 'Gertrude is a cat and Lily is a lion' then Jeff went to the bedroom. It is certain that if either 'Gertrude is a cat' or 'Lily is a lion' but not both then Bernhard is a swan.
It is highly likely that 'John got the apple and Jessica is a mouse'.
There is little chance that 'John got the apple and Jessica is a mouse'.
It is highly likely that 'John got the apple and Jessica is a mouse'.

  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
  0.6::factA.
  0.8::factB.
  0.2::factC.
  %hop1
  0.8::factX:-xor(factB,factA).
  0.0::factY:-and(factC,factB).
  1.0::factZ:-xor(factC,factB).

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

  query(conclusion).
  
'John got the apple and Jessica is a mouse'.