Glasgow Math. J., 34 (1992), 189-192.
1985 Mathematics Subject Classification: primary 46J05; secondary 46H05.
Examples are given of:
(i) a commutative separable normed algebra with an unbounded approximate identity whose completion does not have approximate units;
(ii) a commutative separable Banach algebra with a countable approximate identity and no sequential approximate identity.
Reprints of the paper available on request: e-mail P.Dixon with extension @sheffield.ac.uk.