It is probably the case that Greg is green. Chances are about even that Mary left the football. There is a better than even chance that Emily is a mouse. There is almost no chance that if 'Greg is green and Mary left the football' then Fred dropped the milk. There is a very good chance that if 'Emily is a mouse' or 'Mary left the football' or both then Bernhard is yellow. It is highly likely that if 'Emily is a mouse and Greg is green' then Lily is a lion.
Chances are about even that 'Greg is green and Emily is a mouse'.
Chances are about even that 'Greg is green and Emily is a mouse'.
It is impossible that 'Greg is green and Emily is a mouse'.

  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.
  0.5::factB.
  0.6::factC.
  %hop1
  0.02::factX:-and(factA,factB).
  0.8::factY:-or(factC,factB).
  0.9::factZ:-and(factC,factA).

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

  query(conclusion).
  
'Greg is green and Emily is a mouse'.