I mistyped: E1=E2+EL/2

The + sign should have been an = sign. I didn`t remove my finger from
the dhift register in time and the wrong character emerged (a + instead
of the = sign). I am sorry. It should have read:

E1=E2=EL/2 because EL is the sum of E1 and E2 which are equal.

Best regards, Richard Harrison, KB5WZI