It is certain that Greg is a rhino. There is a better than even chance that Brian is a frog. It is likely that Bernhard is yellow. There is a very good chance that if 'Greg is a rhino' or 'Brian is a frog' or both then Mary went to the garden. There is a better than even chance that if 'Bernhard is yellow and Brian is a frog' then John moved to the office. It is probably not the case that if 'Brian is a frog and Bernhard is yellow' then Lily is a lion.
It is highly unlikely that 'Greg is a rhino' or 'John moved to the office' or both.
It is certain that 'Greg is a rhino' or 'John moved to the office' or both.
It is highly unlikely that 'Greg is a rhino' or 'John moved to the office' 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
  1.0::factA.
  0.6::factB.
  0.7::factC.
  %hop1
  0.8::factX:-or(factA,factB).
  0.6::factY:-and(factC,factB).
  0.25::factZ:-and(factB,factC).

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

  query(conclusion).
  
'Greg is a rhino' or 'John moved to the office' or both.