There is almost no chance that Sandra took the football. It is probable that Greg is white. It is likely that John dropped the apple. It is impossible that if 'Sandra took the football' or 'John dropped the apple' or both then Daniel put down the milk. We believe that if 'Sandra took the football and John dropped the apple' then Lily is a lion. It is probably the case that if 'Sandra took the football' or 'John dropped the apple' or both then Mary went to the garden.
It is impossible that 'Mary went to the garden and John dropped the apple'.
Chances are about even that 'Mary went to the garden and John dropped the apple'.
It is impossible that 'Mary went to the garden and John dropped the apple'.

  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
  0.02::factA.
  0.7::factB.
  0.7::factC.
  %hop1
  0.0::factX:-or(factA,factC).
  0.75::factY:-and(factA,factC).
  0.7::factZ:-or(factA,factC).

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

  query(conclusion).
  
'Mary went to the garden and John dropped the apple'.