What would have been the "result" of Rav Yochanan's Kal Vachomer - Deoraisa, or Deraban. Asssuming Deoraisa, then after the first side of the Kal Vachomer, the Kal Vachomer falls apart! "Uma Torah that does not require a bracha after it ... " - but it is required! You just learned that in a Kal Vachomer!
simon kahn, Jerusalem, Israel
Your question is indeed asked by the Pnei Yehoshua (DH Amar Rebbi Yochanan). His answer is that when Rebbi Yochanan says, "u'Mah Torah...," he does not mean literally that it does not need any Berachah afterwards, but rather that it only requires one Berachah afterwards, as opposed to Birkas ha'Mazon where three Berachos are required afterwards (mid'Oraisa). He discusses whether the Kal va'Chomer is mid'Oraisa, and concludes that it is mid'Oraisa.
All the best,