It is generally attributed to Ronald G. Douglas , although Douglas acknowledges that aspects of the result may already have been known .
In operator theory , an area of mathematics , Douglas ' lemma relates factorization , range inclusion , and majorization of Hilbert space operators .
It is generally attributed to Ronald G. Douglas , although Douglas ' lemma acknowledges that aspects of the result may already have been known .
In operator theory , an area of mathematics , Douglas ' lemma relates factorization , range inclusion , and majorization of Hilbert space operators .