Homework Statement
Prove the following LEMMA:
For every proposition A[P_{1}, \dots, P_{n}] and any two interpretations v and v', if v(P_{i})=v'(P_{i}) for all i=1, \dots,n, then v^{*}(A)=v'^{*}(A).
Homework Equations
The Attempt at a Solution
Sure this is obviously an...