Chances are slight that Brian is green. It is probable that John took the football. We doubt that Julius is a swan. It is highly likely that if 'Brian is green' or 'Julius is a swan' or both then Emily is a wolf. It is impossible that if 'Julius is a swan and John took the football' then Mary put down the milk. It is improbable that if 'Julius is a swan' or 'Brian is green' or both then Lily is yellow.
It is certain that 'Brian is green and John took the football'.
It is highly unlikely that 'Brian is green and John took the football'.
It is certain that 'Brian is green and John took 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
  0.1::factA.
  0.7::factB.
  0.2::factC.
  %hop1
  0.9::factX:-or(factA,factC).
  0.0::factY:-and(factC,factB).
  0.1::factZ:-or(factC,factA).

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

  query(conclusion).
  
'Brian is green and John took the football'.