Chances are slight that John moved to the garden. It is almost certain that Jessica is a mouse. It is probable that Greg is a rhino. Chances are about even that if 'John moved to the garden' or 'Greg is a rhino' or both then Brian is a swan. Chances are slight that if 'John moved to the garden and Jessica is a mouse' then Fred went to the office. There is a better than even chance that if 'Jessica is a mouse and John moved to the garden' then Mary left the football.
It is highly unlikely that 'Jessica is a mouse' or 'John moved to the garden' or both.
It is almost certain that 'Jessica is a mouse' or 'John moved to the garden' or both.
It is highly unlikely that 'Jessica is a mouse' or 'John moved 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
  0.1::factA.
  0.95::factB.
  0.7::factC.
  %hop1
  0.5::factX:-or(factA,factC).
  0.1::factY:-and(factA,factB).
  0.6::factZ:-and(factB,factA).

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

  query(conclusion).
  
'Jessica is a mouse' or 'John moved to the garden' or both.