(1/n) Please help anyone in the know?

Struggling a bit with this David Maister's formula #BigLaw profitability formula.

@grbeaton_law 's #RemakingLawFirms breaks it down by the factors, but I still fail to grasp the following:
(2/n)

1) is "EP" above the line multiplying (I+L), or is it a function of (I+L)? (usually I would assume it is a multiplication, but please note separate multiplication characters that were explicitly written in the latter part)

2) is the "I" in the (I+L) actually "I" or 1?
(3/n) On the above image it seems it is "I" - but "I" is never later defined as a variable, and once later in the text, the (1+L) is mentioned, hence my confusion.
@grbeaton_law thank you very much for any hints - and best of all in the upcoming 2020!
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