A simple application of Pták theory for hermitian Banach algebras, combined with a result on normed Q-algebras, gives a non-technical new proof of the Shirali-Ford theorem. A version of this theorem in the setting of non-normed topological algebras is also provided.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-sm150-2-2, author = {Maria Fragoulopoulou}, title = {The Shirali-Ford theorem as a consequence of Ptak theory for hermitian Banach algebras}, journal = {Studia Mathematica}, volume = {151}, year = {2002}, pages = {121-132}, zbl = {1014.46024}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm150-2-2} }
Maria Fragoulopoulou. The Shirali-Ford theorem as a consequence of Ptak theory for hermitian Banach algebras. Studia Mathematica, Tome 151 (2002) pp. 121-132. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm150-2-2/