It is almost certain that Julius is gray. It is likely that Sandra dropped the milk. It is likely that Brian is green. It is highly unlikely that if 'Julius is gray and Sandra dropped the milk' then Mary went to the office. Chances are about even that if either 'Brian is green' or 'Sandra dropped the milk' but not both then Jeff put down the milk. It is unlikely that if 'Brian is green and Julius is gray' then Greg is a rhino.
There is little chance that 'Brian is green and Greg is a rhino'.
There is little chance that 'Brian is green and Greg is a rhino'.
It is probable that 'Brian is green and Greg is a rhino'.

  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
  0.95::factA.
  0.7::factB.
  0.7::factC.
  %hop1
  0.05::factX:-and(factA,factB).
  0.5::factY:-xor(factC,factB).
  0.2::factZ:-and(factC,factA).

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

  query(conclusion).
  
'Brian is green and Greg is a rhino'.