It is certain that Lily is yellow. It is impossible that Emily is a sheep. It is unlikely that Sandra left the football. It is unlikely that if either 'Lily is yellow' or 'Emily is a sheep' but not both then Brian is white. It is almost certain that if either 'Lily is yellow' or 'Emily is a sheep' but not both then Jeff went to the garden. It is probable that if 'Emily is a sheep and Lily is yellow' then Bill got the milk there.
It is probable that 'Sandra left the football and Emily is a sheep'.
It is impossible that 'Sandra left the football and Emily is a sheep'.
It is probable that 'Sandra left the football and Emily is a sheep'.

  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.
  0.0::factB.
  0.2::factC.
  %hop1
  0.2::factX:-xor(factA,factB).
  0.95::factY:-xor(factA,factB).
  0.7::factZ:-and(factB,factA).

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

  query(conclusion).
  
'Sandra left the football and Emily is a sheep'.