"Proof theoretic justifications of logical laws" (Michael Dummett)(5)

参加者は4人、19時半から参加して22時まで。 "The logical basis of metaphysics" section 11、pp.256-258の"What is an introduction rule?".
single-ended, pure, simple なruleにsheer, oblique (and direct)なrule、覚えられない。結局

We may accordingly recognise as an introduction rule a single-ended rule satisfying the complexity condition

(p.258最終行)。