There is little chance that Fred went to the garden. It is almost certain that Greg is yellow. There is little chance that Lily is yellow. It is unlikely that if 'Lily is yellow' or 'Greg is yellow' or both then Bernhard is a rhino. It is unlikely that if 'Greg is yellow and Lily is yellow' then Sandra dropped the milk. It is unlikely that if 'Lily is yellow and Greg is yellow' then John discarded the milk.
It is almost certain that 'Lily is yellow' or 'Greg is yellow' or both.
It is almost certain that 'Lily is yellow' or 'Greg is yellow' or both.
It is improbable that 'Lily is yellow' or 'Greg is yellow' 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
  0.1::factA.
  0.95::factB.
  0.1::factC.
  %hop1
  0.2::factX:-or(factC,factB).
  0.2::factY:-and(factB,factC).
  0.2::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Lily is yellow' or 'Greg is yellow' or both.