It is impossible that Jessica is a cat. There is little chance that Lily is a frog. There is a very good chance that Greg is white. It is highly likely that if 'Lily is a frog and Greg is white' then Emily is a mouse. It is probable that if 'Greg is white and Jessica is a cat' then Brian is green. Chances are about even that if 'Lily is a frog and Jessica is a cat' then John went to the garden.
There is a very good chance that 'Jessica is a cat' or 'Greg is white' or both.
There is a very good chance that 'Jessica is a cat' or 'Greg is white' or both.
It is impossible that 'Jessica is a cat' or 'Greg is white' or both.

  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
  0.0::factA.
  0.1::factB.
  0.8::factC.
  %hop1
  0.9::factX:-and(factB,factC).
  0.7::factY:-and(factC,factA).
  0.5::factZ:-and(factB,factA).

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

  query(conclusion).
  
'Jessica is a cat' or 'Greg is white' or both.