It is certain that Julius is gray. There is a very good chance that Greg is a frog. It is probable that Lily is a lion. It is highly unlikely that if either 'Lily is a lion' or 'Greg is a frog' but not both then John dropped the apple. There is little chance that if either 'Julius is gray' or 'Lily is a lion' but not both then Bill went to the office. There is little chance that if either 'Greg is a frog' or 'Julius is gray' but not both then Bernhard is yellow.
It is highly likely that 'Bill went to the office and Lily is a lion'.
It is impossible that 'Bill went to the office and Lily is a lion'.
It is highly likely that 'Bill went to the office and Lily is a lion'.

  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
  1.0::factA.
  0.8::factB.
  0.7::factC.
  %hop1
  0.05::factX:-xor(factC,factB).
  0.1::factY:-xor(factA,factC).
  0.1::factZ:-xor(factB,factA).

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

  query(conclusion).
  
'Bill went to the office and Lily is a lion'.