It is probably not the case that Bill went to the office. It is impossible that Julius is a frog. It is highly likely that Emily is a sheep. It is probable that if either 'Julius is a frog' or 'Emily is a sheep' but not both then Jason is thirsty. We believe that if either 'Emily is a sheep' or 'Bill went to the office' but not both then Greg is white. Chances are slight that if 'Julius is a frog' or 'Bill went to the office' or both then John got the football.
There is a very good chance that 'Bill went to the office and Jason is thirsty'.
We doubt that 'Bill went to the office and Jason is thirsty'.
There is a very good chance that 'Bill went to the office 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
  0.25::factA.
  0.0::factB.
  0.9::factC.
  %hop1
  0.7::factX:-xor(factB,factC).
  0.75::factY:-xor(factC,factA).
  0.1::factZ:-or(factB,factA).

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

  query(conclusion).
  
'Bill went to the office and Jason is thirsty'.