It is improbable that Mary discarded the milk. There is little chance that Greg is a rhino. It is likely that Jason is tired. It is certain that if either 'Greg is a rhino' or 'Mary discarded the milk' but not both then Emily is a mouse. It is probable that if either 'Mary discarded the milk' or 'Jason is tired' but not both then Julius is a swan. It is unlikely that if 'Jason is tired and Greg is a rhino' then Bill went to the garden.
Chances are about even that 'Bill went to the garden' or 'Julius is a swan' or both.
Chances are about even that 'Bill went to the garden' or 'Julius is a swan' or both.
It is impossible that 'Bill went to the garden' or 'Julius is a swan' 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
  1.0::factX:-xor(factB,factA).
  0.7::factY:-xor(factA,factC).
  0.2::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Bill went to the garden' or 'Julius is a swan' or both.