There is a better than even chance that John went to the garden. It is impossible that Lily is white. It is unlikely that Brian is a rhino. Chances are slight that if either 'Lily is white' or 'John went to the garden' but not both then Gertrude is a sheep. It is impossible that if 'John went to the garden and Lily is white' then Bernhard is a frog. Chances are about even that if either 'Lily is white' or 'John went to the garden' but not both then Mary left the football.
It is probably not the case that 'Mary left the football' or 'Bernhard is a frog' or both.
It is probably not the case that 'Mary left the football' or 'Bernhard is a frog' or both.
It is highly likely that 'Mary left the football' or 'Bernhard is a frog' 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
  0.6::factA.
  0.0::factB.
  0.2::factC.
  %hop1
  0.1::factX:-xor(factB,factA).
  0.0::factY:-and(factA,factB).
  0.5::factZ:-xor(factB,factA).

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

  query(conclusion).
  
'Mary left the football' or 'Bernhard is a frog' or both.