Existential Generalization
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
From Fa, derive (∃x)Fx. What's true of a named thing is true of something.
Show
Ms, therefore (∃x)Mx. Socrates is mortal, so something is.
Watch for
EG is as generous as UI. The two generalizations differ wildly in strictness; the two instantiations do too — crosswise.