CL - 5x - Supplementary on Sequents
From Haoran Peng
This video includes a couple of points from a 2019 review lecture on Sequents.
First we discuss how to use reduction to find an inhabited model in which Γ ⊨ Δ, which is equivalent to finding a model such that Γ ⊭ ¬(⨈ Δ) .
Then we discuss a confusion arising from our shorthand notation for sets of sequents on either side of the turnstile. What should we mean by ∅ ⊨ ∅?