There is little chance that John went to the garden. It is probable that Bill got the milk there. It is impossible that Mary left the apple. It is almost certain that if 'Bill got the milk there' or 'Mary left the apple' or both then Lily is yellow. There is little chance that if 'John went to the garden' or 'Bill got the milk there' or both then Julius is a frog. It is highly unlikely that if 'John went to the garden and Mary left the apple' then Greg is green.
We believe that 'John went to the garden' or 'Bill got the milk there' or both.
We believe that 'John went to the garden' or 'Bill got the milk there' or both.
We doubt that 'John went to the garden' or 'Bill got the milk there' 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.
  0.7::factB.
  0.0::factC.
  %hop1
  0.95::factX:-or(factB,factC).
  0.1::factY:-or(factA,factB).
  0.05::factZ:-and(factA,factC).

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

  query(conclusion).
  
'John went to the garden' or 'Bill got the milk there' or both.