It is probably not the case that Lily is a frog. It is impossible that Greg is a rhino. There is little chance that Mary dropped the milk. It is probably not the case that if 'Lily is a frog' or 'Mary dropped the milk' or both then Emily is a wolf. There is a better than even chance that if 'Lily is a frog and Greg is a rhino' then John picked up the apple. It is improbable that if either 'Lily is a frog' or 'Mary dropped the milk' but not both then Brian is a swan.
It is impossible that 'Greg is a rhino and John picked up the apple'.
It is impossible that 'Greg is a rhino and John picked up the apple'.
It is probably the case that 'Greg is a rhino and John picked up the apple'.

  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
  0.25::factA.
  0.0::factB.
  0.1::factC.
  %hop1
  0.25::factX:-or(factA,factC).
  0.6::factY:-and(factA,factB).
  0.1::factZ:-xor(factA,factC).

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

  query(conclusion).
  
'Greg is a rhino and John picked up the apple'.