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import Mathlib
-- Or just import Mathlib.Util.CountHeartbeats

-- This is how you benchmark stuff I think
#count_heartbeats in
example {a b : ℝ} (hab : a * b ≤ 0) (ha : a ≠ 0) (hb : b ≠ 0) : (0 < a ∧ b < 0) ∨ (a < 0 ∧ 0 < b) := by
  grind [mul_nonpos_iff_neg_imp_nonneg.mp hab]