Doing so requires some notational care. In many texts discussing charge conjugation, the involution formula_80 is not given an explicit symbolic name, when applied to "single-particle solutions" of the Dirac equation. This is in contrast to the case when the "quantized field" is discussed, where a unitary operator formula_81 is defined (as done in a later section, below). For the present section, let the involution be named as formula_82 so that formula_83 Taking this to be a linear operator, one may consider its eigenstates. The Majorana condition singles out one such: formula_84 There are, however, two such eigenstates: formula_85 Continuing in the Weyl basis, as above, these eigenstates are