It is probable that John went to the kitchen. It is probably not the case that Julius is a frog. It is certain that Mary left the football. It is improbable that if 'Julius is a frog and John went to the kitchen' then Bernhard is yellow. It is highly likely that if either 'John went to the kitchen' or 'Julius is a frog' but not both then Brian is a rhino. There is little chance that if 'John went to the kitchen and Julius is a frog' then Greg is a lion.
It is probably not the case that 'Bernhard is yellow' or 'Julius is a frog' or both.
It is probably not the case that 'Bernhard is yellow' or 'Julius is a frog' or both.
It is certain that 'Bernhard is yellow' or 'Julius is a frog' or 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
  0.7::factA.
  0.25::factB.
  1.0::factC.
  %hop1
  0.1::factX:-and(factB,factA).
  0.9::factY:-xor(factA,factB).
  0.1::factZ:-and(factA,factB).

  %hop2
  conclusion:-or(factX,factB).

  query(conclusion).
  
'Bernhard is yellow' or 'Julius is a frog' or both.