Quote Originally Posted by Sneaky View Post
Can I write it like this:

Claim: ∀n∈ℕ>0, ∀t∈ℕ, 0≤t<2^n → ∃ subset A s.t. A⊆B_n ˄ ∑[x∈A]x = t.

Let P(n) be the predicate that ∀t, 0≤t<2^n → ∃ subset A s.t. A⊆B_n ˄ ∑[x∈A]x = t.
Excellent.