Answer:
Step-by-step explanation:
Derive the validity of universal form of part(a) of the elimination rule from the validity of universal instantiation and the valid argument called elimination in Section 2.3.
P(x)∨Q(x)
~Q(x)
∵ P(x)
Universal Instantiation has the following argument form
∀ x ∈ D, P (x)
P(a) for a particular a∈D
Universal Elimination Rule:
∀x, P(x)
∵~ P(a)
Here is a particular value.
P(a) For a particular a∈D
Since the universal elimination is same as universal instantiation.
Therefore, Universal elimination is valid when universal instantiation and elimination rule are valid
