Chances are about even that Sandra left the apple. It is certain that John moved to the office. There is little chance that Brian is a rhino. It is probably not the case that if 'Brian is a rhino' or 'Sandra left the apple' or both then Bernhard is gray. It is unlikely that if either 'Brian is a rhino' or 'Sandra left the apple' but not both then Greg is a frog. It is certain that if either 'Sandra left the apple' or 'John moved to the office' but not both then Julius is yellow.
We believe that 'Brian is a rhino and John moved to the office'.
It is improbable that 'Brian is a rhino and John moved to the office'.
We believe that 'Brian is a rhino and John moved to the office'.

  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
  0.5::factA.
  1.0::factB.
  0.1::factC.
  %hop1
  0.25::factX:-or(factC,factA).
  0.2::factY:-xor(factC,factA).
  1.0::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Brian is a rhino and John moved to the office'.