There is a better than even chance that Julius is gray. There is a better than even chance that John took the apple. It is highly unlikely that Greg is a rhino. It is likely that if 'Greg is a rhino' or 'Julius is gray' or both then Jessica is a cat. It is improbable that if either 'Greg is a rhino' or 'Julius is gray' but not both then Sandra dropped the milk. It is highly unlikely that if either 'Greg is a rhino' or 'Julius is gray' but not both then Bernhard is a swan.
It is probably not the case that 'John took the apple and Julius is gray'.
It is probably not the case that 'John took the apple and Julius is gray'.
It is highly likely that 'John took the apple and Julius is gray'.

  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
  0.6::factA.
  0.6::factB.
  0.05::factC.
  %hop1
  0.7::factX:-or(factC,factA).
  0.1::factY:-xor(factC,factA).
  0.05::factZ:-xor(factC,factA).

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

  query(conclusion).
  
'John took the apple and Julius is gray'.