It is probable that Lily is yellow. It is impossible that Jessica is a cat. It is probably not the case that John went to the hallway. Chances are about even that if either 'Jessica is a cat' or 'Lily is yellow' but not both then Winona is a mouse. It is certain that if 'Lily is yellow and Jessica is a cat' then Brian is a rhino. It is improbable that if 'Jessica is a cat and Lily is yellow' then Daniel took the football.
It is probably not the case that 'Brian is a rhino' or 'John went to the hallway' or both.
It is probably not the case that 'Brian is a rhino' or 'John went to the hallway' or both.
It is certain that 'Brian is a rhino' or 'John went to the hallway' or both.

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

  %hop2
  conclusion:-or(factY,factC).

  query(conclusion).
  
'Brian is a rhino' or 'John went to the hallway' or both.