We believe that Brian is a frog. It is improbable that Daniel got the football. There is little chance that Mary moved to the office. It is almost certain that if 'Brian is a frog' or 'Mary moved to the office' or both then Bernhard is a swan. It is highly likely that if 'Brian is a frog' or 'Mary moved to the office' or both then Emily is a wolf. There is little chance that if 'Brian is a frog and Mary moved to the office' then Julius is a lion.
It is highly likely that 'Mary moved to the office and Brian is a frog'.
It is improbable that 'Mary moved to the office and Brian is a frog'.
It is highly likely that 'Mary moved to the office and Brian is a frog'.

  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
  0.75::factA.
  0.1::factB.
  0.1::factC.
  %hop1
  0.95::factX:-or(factA,factC).
  0.9::factY:-or(factA,factC).
  0.1::factZ:-and(factA,factC).

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

  query(conclusion).
  
'Mary moved to the office and Brian is a frog'.