There is a better than even chance that Fred left the football. It is almost certain that Brian is green. It is highly likely that Lily is a swan. It is highly likely that if either 'Brian is green' or 'Lily is a swan' but not both then Gertrude is a cat. It is impossible that if either 'Fred left the football' or 'Lily is a swan' but not both then Mary went to the office. It is probably not the case that if either 'Fred left the football' or 'Brian is green' but not both then Daniel took the apple.
It is impossible that 'Fred left the football and Mary went to the office'.
It is impossible that 'Fred left the football and Mary went to the office'.
Chances are about even that 'Fred left the football and Mary went to the office'.

  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.
  0.95::factB.
  0.9::factC.
  %hop1
  0.9::factX:-xor(factB,factC).
  0.0::factY:-xor(factA,factC).
  0.25::factZ:-xor(factA,factB).

  %hop2
  conclusion:-and(factA,factY).

  query(conclusion).
  
'Fred left the football and Mary went to the office'.