It is almost certain that Mary went to the office. It is almost certain that Greg is a swan. It is impossible that Jason is tired. It is highly unlikely that if 'Mary went to the office' or 'Jason is tired' or both then Brian is a swan. It is probably the case that if 'Greg is a swan' or 'Mary went to the office' or both then Lily is a frog. It is likely that if either 'Jason is tired' or 'Greg is a swan' but not both then Daniel got the apple.
It is almost certain that 'Mary went to the office' or 'Jason is tired' or both.
It is almost certain that 'Mary went to the office' or 'Jason is tired' or both.
Chances are slight that 'Mary went to the office' or 'Jason is tired' 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
  0.95::factA.
  0.95::factB.
  0.0::factC.
  %hop1
  0.05::factX:-or(factA,factC).
  0.7::factY:-or(factB,factA).
  0.7::factZ:-xor(factC,factB).

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

  query(conclusion).
  
'Mary went to the office' or 'Jason is tired' or both.