There is almost no chance that Mary went to the kitchen. Chances are about even that Brian is green. We believe that Daniel took the football. Chances are about even that if 'Brian is green and Daniel took the football' then Yann is thirsty. Chances are slight that if either 'Brian is green' or 'Mary went to the kitchen' but not both then Greg is a rhino. It is highly likely that if 'Brian is green and Daniel took the football' then Lily is gray.
We believe that 'Daniel took the football' or 'Greg is a rhino' or both.
We believe that 'Daniel took the football' or 'Greg is a rhino' or both.
There is little chance that 'Daniel took the football' or 'Greg is a rhino' 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
  0.02::factA.
  0.5::factB.
  0.75::factC.
  %hop1
  0.5::factX:-and(factB,factC).
  0.1::factY:-xor(factB,factA).
  0.9::factZ:-and(factB,factC).

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

  query(conclusion).
  
'Daniel took the football' or 'Greg is a rhino' or both.