It is probably the case that Brian is a rhino. It is probable that Julius is a swan. It is improbable that John left the football. It is certain that if 'Brian is a rhino and Julius is a swan' then Mary got the apple. It is likely that if either 'Julius is a swan' or 'John left the football' but not both then Bernhard is a frog. We believe that if 'Julius is a swan' or 'John left the football' or both then Greg is green.
It is highly unlikely that 'Julius is a swan and John left the football'.
It is highly unlikely that 'Julius is a swan and John left the football'.
It is probably the case that 'Julius is a swan and John left the football'.

  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
  0.7::factA.
  0.7::factB.
  0.1::factC.
  %hop1
  1.0::factX:-and(factA,factB).
  0.7::factY:-xor(factB,factC).
  0.75::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Julius is a swan and John left the football'.