It is highly likely that Gertrude is a mouse. It is almost certain that Mary got the football. It is unlikely that John is in the garden. Chances are slight that if 'Mary got the football and Gertrude is a mouse' then Sandra dropped the milk. We doubt that if 'John is in the garden and Mary got the football' then Brian is a swan. It is unlikely that if either 'John is in the garden' or 'Mary got the football' but not both then Lily is white.
It is likely that 'Mary got the football and John is in the garden'.
We doubt that 'Mary got the football and John is in the garden'.
It is likely that 'Mary got the football and John is in the garden'.

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

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

  query(conclusion).
  
'Mary got the football and John is in the garden'.