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Universal Instantiation

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State

From (x)Fx, derive Fa — or Fy — for any constant or variable. What's true of everything is true of each thing.

Show

(x)(Hx ⊃ Mx), so Hs ⊃ Ms. Socrates inherits the rule.

Watch for

UI is generous — instantiate to anything. The other three quantifier rules are not so relaxed.