In: Advanced Math
Structural Induction on WFF For a formula α ∈ WFF we let `(α) denote the number of symbols in α that are left brackets ‘(’, let v(α) the number of variable symbols, and c(α) the number of symbols that are the corner symbol ‘¬’. For example in ((p1 → p2) ∧ ((¬p1) → p2)) we have `(α) = 4, v(α) = 4 and c(α) = 1. Prove by induction that he following property holds for all well formed formulas: • `(α) = v(α) + c(α) − 1