There is little chance that Mary got the apple. It is probably the case that John moved to the garden. We believe that Greg is yellow. It is certain that if either 'Mary got the apple' or 'Greg is yellow' but not both then Fred went to the office. Chances are slight that if 'Mary got the apple and Greg is yellow' then Brian is a lion. It is probably not the case that if 'Greg is yellow and John moved to the garden' then Julius is a rhino.
It is highly unlikely that 'Mary got the apple and John moved to the garden'.
It is highly unlikely that 'Mary got the apple and John moved to the garden'.
It is probable that 'Mary got the apple and John 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
  0.1::factA.
  0.7::factB.
  0.75::factC.
  %hop1
  1.0::factX:-xor(factA,factC).
  0.1::factY:-and(factA,factC).
  0.25::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Mary got the apple and John moved to the garden'.