There is little chance that John went to the kitchen. There is little chance that Gertrude is a sheep. It is probable that Lily is green. Chances are about even that if 'John went to the kitchen and Lily is green' then Sandra took the football. There is almost no chance that if 'John went to the kitchen and Lily is green' then Daniel grabbed the milk. There is almost no chance that if 'John went to the kitchen and Lily is green' then Jessica is a cat.
We believe that 'Gertrude is a sheep' or 'Lily is green' or both.
We believe that 'Gertrude is a sheep' or 'Lily is green' or both.
It is probably not the case that 'Gertrude is a sheep' or 'Lily is green' 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.
  0.1::factB.
  0.7::factC.
  %hop1
  0.5::factX:-and(factA,factC).
  0.02::factY:-and(factA,factC).
  0.02::factZ:-and(factA,factC).

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

  query(conclusion).
  
'Gertrude is a sheep' or 'Lily is green' or both.