
theorem
  for x,y,z being Element of BOOLEAN holds or3.<*x,y,z*> = x 'or' y 'or'
  z & or3a.<*x,y,z*> = 'not' x 'or' y 'or' z & or3b.<*x,y,z*> = 'not' x 'or'
  'not' y 'or' z & nand3.<*x,y,z*> = 'not' x 'or' 'not' y 'or' 'not' z
    by FACIRC_1:def 7
