It is probably the case that Lily is a rhino. We believe that Gertrude is a mouse. It is highly unlikely that John dropped the milk. We doubt that if either 'Gertrude is a mouse' or 'John dropped the milk' but not both then Bill left the football. It is unlikely that if 'Gertrude is a mouse' or 'Lily is a rhino' or both then Bernhard is green. There is almost no chance that if 'Gertrude is a mouse' or 'John dropped the milk' or both then Mary went to the bedroom.
It is impossible that 'Bill left the football and Mary went to the bedroom'.
It is impossible that 'Bill left the football and Mary went to the bedroom'.
It is likely that 'Bill left the football and Mary went to the bedroom'.

  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.
  0.75::factB.
  0.05::factC.
  %hop1
  0.2::factX:-xor(factB,factC).
  0.2::factY:-or(factB,factA).
  0.02::factZ:-or(factB,factC).

  %hop2
  conclusion:-and(factX,factZ).

  query(conclusion).
  
'Bill left the football and Mary went to the bedroom'.