Quote:
A single supply op amp can probably serve a split-supply
application but the converse is not likely true (otherwise
they would market it that way).
???
Do you really think that a normal - for split supply designed - opamp cannot be operated with single supply ? Of course, each opamp is able to work with a single supply if it is biased properly!
An opamp needs a voltage (that means: a potential difference) between its supply nodes - and it does not matter at all if this voltage is supplied by one or by two sources.