We believe that John took the apple. It is almost certain that Fred went to the garden. There is a very good chance that Jason is tired. It is unlikely that if either 'Jason is tired' or 'John took the apple' but not both then Gertrude is a sheep. It is almost certain that if 'Fred went to the garden' or 'Jason is tired' or both then Greg is yellow. We doubt that if either 'John took the apple' or 'Fred went to the garden' but not both then Brian is a rhino.
There is almost no chance that 'Fred went to the garden' or 'Jason is tired' or both.
It is certain that 'Fred went to the garden' or 'Jason is tired' or both.
There is almost no chance that 'Fred went to the garden' or 'Jason is tired' 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
  0.75::factA.
  0.95::factB.
  0.8::factC.
  %hop1
  0.2::factX:-xor(factC,factA).
  0.95::factY:-or(factB,factC).
  0.2::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Fred went to the garden' or 'Jason is tired' or both.