I was just introduced a new grammar point, the も~も construction as shown on https://core6000.neocities.org/dojg/. I understand the main function of も and how it is the inclusionary particle and I can follow along with most of the examples for the grammar point that the site provides, but I can't make out how sentences with ば (I've only known the form to be the conditional. Haven't done grammar lookups in j-j dictionaries) are working.
One of the samples sentences provided is
彼は親戚でもなければ友達でもない。
and the english interpretation is "He is neither a relative nor a friend." My question is how does なければ, what I would think would be the ば conditional of ない, work here? Literal English translations aren't doing me much good here if I try and translate this taking ば as the conditional. Can someone help me understand how this is working?