Chances are about even that Jason is thirsty. It is highly likely that Sandra got the football. There is little chance that Brian is white. Chances are about even that if 'Sandra got the football' or 'Brian is white' or both then John discarded the apple. It is highly likely that if either 'Sandra got the football' or 'Brian is white' but not both then Greg is yellow. It is likely that if either 'Brian is white' or 'Sandra got the football' but not both then Bernhard is a rhino.
There is a very good chance that 'John discarded the apple and Jason is thirsty'.
It is probably not the case that 'John discarded the apple and Jason is thirsty'.
There is a very good chance that 'John discarded the apple and Jason is thirsty'.

  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
  0.5::factA.
  0.9::factB.
  0.1::factC.
  %hop1
  0.5::factX:-or(factB,factC).
  0.9::factY:-xor(factB,factC).
  0.7::factZ:-xor(factC,factB).

  %hop2
  conclusion:-and(factX,factA).

  query(conclusion).
  
'John discarded the apple and Jason is thirsty'.