a=rε,b=s+δ,
This should be \(a = r + \varepsilon\) (not \(a=r\varepsilon\)), so that the next block, $$ ab = (r + \varepsilon)(s + \delta) $$ is correct.
a=rε,b=s+δ,
This should be \(a = r + \varepsilon\) (not \(a=r\varepsilon\)), so that the next block, $$ ab = (r + \varepsilon)(s + \delta) $$ is correct.
There is an error in Thereom 1.6.2: (ii) and (iii) are identical statements. Was (iii) supposed to say "If \(b\) is infinite, so is \(a\)."?