There is a very good chance that Sandra dropped the apple. It is probably not the case that Mary moved to the garden. It is highly likely that Greg is green. It is probable that if either 'Greg is green' or 'Sandra dropped the apple' but not both then Julius is a rhino. It is highly unlikely that if 'Sandra dropped the apple and Greg is green' then John put down the milk. It is probably the case that if either 'Mary moved to the garden' or 'Greg is green' but not both then Brian is a frog.
We believe that 'John put down the milk and Julius is a rhino'.
It is impossible that 'John put down the milk and Julius is a rhino'.
We believe that 'John put down the milk and Julius 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
  0.8::factA.
  0.25::factB.
  0.9::factC.
  %hop1
  0.7::factX:-xor(factC,factA).
  0.05::factY:-and(factA,factC).
  0.7::factZ:-xor(factB,factC).

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

  query(conclusion).
  
'John put down the milk and Julius is a rhino'.