There is a very good chance that Sandra grabbed the apple. It is highly likely that Gertrude is a cat. Chances are about even that Jessica is a mouse. It is unlikely that if 'Gertrude is a cat and Jessica is a mouse' then Lily is a rhino. It is highly likely that if 'Sandra grabbed the apple' or 'Gertrude is a cat' or both then Emily is a wolf. There is almost no chance that if 'Sandra grabbed the apple' or 'Jessica is a mouse' or both then Mary went to the garden.
There is almost no chance that 'Mary went to the garden and Jessica is a mouse'.
There is almost no chance that 'Mary went to the garden and Jessica is a mouse'.
It is almost certain that 'Mary went to the garden 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
  0.8::factA.
  0.9::factB.
  0.5::factC.
  %hop1
  0.2::factX:-and(factB,factC).
  0.9::factY:-or(factA,factB).
  0.02::factZ:-or(factA,factC).

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

  query(conclusion).
  
'Mary went to the garden and Jessica is a mouse'.