  Overall, Weyl’s treatment is quite modern except for the confusion  regarding the positive electron (anti-electron) that at that time was identified with the proton rather than with the positron, which was  discovered a few years later. Weyl was quite concerned about the  identification of the proton with the positive electron because his  analysis of the discrete symmetries \(\mathbf{C}, \mathbf{P}, \mathbf{T}\) and  \(\mathbf{CPT}\) led him to conclude that the mass of the positive electron should equal the mass of the   electron.[106] 