Chances are slight that Lily is a rhino. There is a better than even chance that John went to the kitchen. It is certain that Greg is gray. It is probably not the case that if 'Lily is a rhino and Greg is gray' then Mary left the football. It is impossible that if 'John went to the kitchen' or 'Greg is gray' or both then Jessica is a mouse. It is probable that if 'Lily is a rhino' or 'John went to the kitchen' or both then Brian is a frog.
There is almost no chance that 'Brian is a frog and Mary left the football'.
There is almost no chance that 'Brian is a frog and Mary left the football'.
There is a very good chance that 'Brian is a frog and Mary left the football'.

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

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

  query(conclusion).
  
'Brian is a frog and Mary left the football'.