Chances are about even that Sandra left the apple. It is highly unlikely that Emily is a mouse. It is certain that Mary picked up the milk. It is improbable that if 'Emily is a mouse and Sandra left the apple' then John went to the hallway. There is a better than even chance that if either 'Sandra left the apple' or 'Emily is a mouse' but not both then Julius is a rhino. It is impossible that if 'Mary picked up the milk' or 'Sandra left the apple' or both then Brian is a frog.
It is certain that 'John went to the hallway and Julius is a rhino'.
It is impossible that 'John went to the hallway and Julius is a rhino'.
It is certain that 'John went to the hallway and Julius is a rhino'.

  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
  0.5::factA.
  0.05::factB.
  1.0::factC.
  %hop1
  0.1::factX:-and(factB,factA).
  0.6::factY:-xor(factA,factB).
  0.0::factZ:-or(factC,factA).

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

  query(conclusion).
  
'John went to the hallway and Julius is a rhino'.