∀[a,b:ℚ]. uiff(a = qavg(a;b) ∈ ℚ;a = b ∈ ℚ)
{ (Unfold `qavg` 0 THEN Auto) }
1. a : ℚ
2. b : ℚ
3. a = (a + b/2) ∈ ℚ
⊢ a = b ∈ ℚ
3. a = b ∈ ℚ
⊢ a = (a + b/2) ∈ ℚ