[see also: strength
The next lemma is the first in this section that seems to require the full force of the normality of X.
The assumptions of Section 3 are still in force except that for greater generality we do not assume f to be continuous.
[see also: make, necessitate, impose, require] If we choose μ close to 1, we can force r<0.
This forces f to satisfy (6).
We find ourselves forced to introduce an extra assumption.