There is little chance that Emily is a cat. It is highly likely that Greg is a frog. It is highly unlikely that John went to the office. It is impossible that if either 'Greg is a frog' or 'Emily is a cat' but not both then Lily is white. It is likely that if either 'John went to the office' or 'Emily is a cat' but not both then Julius is a rhino. It is certain that if either 'John went to the office' or 'Greg is a frog' but not both then Mary left the football.
It is impossible that 'John went to the office and Emily is a cat'.
It is impossible that 'John went to the office and Emily is a cat'.
There is a better than even chance that 'John went to the office and Emily is a cat'.

  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.
  0.9::factB.
  0.05::factC.
  %hop1
  0.0::factX:-xor(factB,factA).
  0.7::factY:-xor(factC,factA).
  1.0::factZ:-xor(factC,factB).

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

  query(conclusion).
  
'John went to the office and Emily is a cat'.