It is likely that Brian is a frog. It is probably not the case that Jeff moved to the office. There is little chance that Greg is green. It is probably the case that if either 'Jeff moved to the office' or 'Greg is green' but not both then Sandra left the milk. It is certain that if 'Greg is green and Jeff moved to the office' then Bernhard is yellow. There is little chance that if either 'Greg is green' or 'Brian is a frog' but not both then Julius is white.
Chances are slight that 'Brian is a frog and Sandra left the milk'.
Chances are slight that 'Brian is a frog and Sandra left the milk'.
It is certain that 'Brian is a frog and Sandra left the milk'.

  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
  0.7::factA.
  0.25::factB.
  0.1::factC.
  %hop1
  0.7::factX:-xor(factB,factC).
  1.0::factY:-and(factC,factB).
  0.1::factZ:-xor(factC,factA).

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

  query(conclusion).
  
'Brian is a frog and Sandra left the milk'.