We doubt that Brian is a rhino. It is probably not the case that Fred put down the apple. We believe that John got the milk. We believe that if either 'Brian is a rhino' or 'John got the milk' but not both then Mary went to the hallway. It is unlikely that if 'Fred put down the apple and Brian is a rhino' then Sandra took the football. There is little chance that if 'John got the milk and Brian is a rhino' then Lily is a lion.
It is highly unlikely that 'Sandra took the football' or 'Mary went to the hallway' or both.
Chances are about even that 'Sandra took the football' or 'Mary went to the hallway' or both.
It is highly unlikely that 'Sandra took the football' or 'Mary went to the hallway' 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
  0.2::factA.
  0.25::factB.
  0.75::factC.
  %hop1
  0.75::factX:-xor(factA,factC).
  0.2::factY:-and(factB,factA).
  0.1::factZ:-and(factC,factA).

  %hop2
  conclusion:-or(factY,factX).

  query(conclusion).
  
'Sandra took the football' or 'Mary went to the hallway' or both.