import Mathlib.Algebra.BigOperators.Basic import Mathlib import TestGame.Metadata set_option tactic.hygienic false Game "TestGame" World "Induction" Level 1 Title "Simp" Introduction " " Statement "" (n : ℕ) : True := by trivial NewTactics simp -- Σ_i Σ_j ... = Σ_j Σ_i ... -- rw [sum_comm] example : ¬ ∀ (x : ℕ), x ≥ 10 := by push_neg use 5 simp ¬ ∀ (...) ↔ ∃ (¬ ...)