It is highly likely that Brian is green. There is a very good chance that Gertrude is a sheep. It is almost certain that Julius is white. It is probably the case that if 'Gertrude is a sheep and Julius is white' then Jeff dropped the apple. We doubt that if either 'Brian is green' or 'Gertrude is a sheep' but not both then Mary left the football. It is likely that if either 'Julius is white' or 'Brian is green' but not both then Lily is a rhino.
There is little chance that 'Gertrude is a sheep and Julius is white'.
We believe that 'Gertrude is a sheep and Julius is white'.
There is little chance that 'Gertrude is a sheep and Julius is white'.

  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
  0.9::factA.
  0.8::factB.
  0.95::factC.
  %hop1
  0.7::factX:-and(factB,factC).
  0.2::factY:-xor(factA,factB).
  0.7::factZ:-xor(factC,factA).

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

  query(conclusion).
  
'Gertrude is a sheep and Julius is white'.