It is certain that Mary went to the office. There is little chance that Bernhard is yellow. It is probably not the case that Daniel got the football. It is probably not the case that if either 'Daniel got the football' or 'Bernhard is yellow' but not both then Gertrude is a wolf. There is a better than even chance that if either 'Daniel got the football' or 'Mary went to the office' but not both then Brian is a frog. It is highly unlikely that if 'Bernhard is yellow and Daniel got the football' then Lily is a rhino.
It is probably not the case that 'Gertrude is a wolf' or 'Daniel got the football' or both.
It is probably not the case that 'Gertrude is a wolf' or 'Daniel got the football' or both.
It is likely that 'Gertrude is a wolf' or 'Daniel got the football' 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
  1.0::factA.
  0.1::factB.
  0.25::factC.
  %hop1
  0.25::factX:-xor(factC,factB).
  0.6::factY:-xor(factC,factA).
  0.05::factZ:-and(factB,factC).

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

  query(conclusion).
  
'Gertrude is a wolf' or 'Daniel got the football' or both.