Chances are slight that Sandra got the football. Chances are about even that Julius is a frog. It is highly likely that Emily is a cat. It is almost certain that if either 'Sandra got the football' or 'Julius is a frog' but not both then Gertrude is a sheep. It is probably the case that if 'Sandra got the football and Julius is a frog' then Greg is green. It is improbable that if either 'Emily is a cat' or 'Julius is a frog' but not both then Lily is a lion.
There is almost no chance that 'Gertrude is a sheep and Emily is a cat'.
Chances are about even that 'Gertrude is a sheep and Emily is a cat'.
There is almost no chance that 'Gertrude is a sheep and Emily is a cat'.

  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.
  0.5::factB.
  0.9::factC.
  %hop1
  0.95::factX:-xor(factA,factB).
  0.7::factY:-and(factA,factB).
  0.1::factZ:-xor(factC,factB).

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

  query(conclusion).
  
'Gertrude is a sheep and Emily is a cat'.