There is almost no chance that John moved to the office. It is probably the case that Lily is a frog. There is little chance that Greg is yellow. It is highly likely that if either 'Lily is a frog' or 'Greg is yellow' but not both then Gertrude is a cat. There is almost no chance that if 'Greg is yellow' or 'Lily is a frog' or both then Jeff went to the bedroom. It is impossible that if 'John moved to the office and Lily is a frog' then Emily is a mouse.
It is highly likely that either 'Emily is a mouse' or 'Greg is yellow' but not both.
Chances are slight that either 'Emily is a mouse' or 'Greg is yellow' but not both.
It is highly likely that either 'Emily is a mouse' or 'Greg is yellow' but not 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.
  0.7::factB.
  0.1::factC.
  %hop1
  0.9::factX:-xor(factB,factC).
  0.02::factY:-or(factC,factB).
  0.0::factZ:-and(factA,factB).

  %hop2
  conclusion:-xor(factZ,factC).

  query(conclusion).
  
Either 'Emily is a mouse' or 'Greg is yellow' but not both.