There is almost no chance that Brian is a frog. It is probably the case that Jeff moved to the office. We believe that Julius is yellow. There is little chance that if either 'Brian is a frog' or 'Jeff moved to the office' but not both then Bernhard is gray. Chances are slight that if 'Brian is a frog' or 'Julius is yellow' or both then Lily is a rhino. There is little chance that if 'Jeff moved to the office' or 'Brian is a frog' or both then Mary left the football.
Chances are about even that 'Mary left the football and Julius is yellow'.
It is highly unlikely that 'Mary left the football and Julius is yellow'.
Chances are about even that 'Mary left the football and Julius is yellow'.

  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.
  0.75::factC.
  %hop1
  0.1::factX:-xor(factA,factB).
  0.1::factY:-or(factA,factC).
  0.1::factZ:-or(factB,factA).

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

  query(conclusion).
  
'Mary left the football and Julius is yellow'.