a b r : ℝ≥0
hr : r ≠ 0
this : 0 < r
⊢ r * a ≤ b ↔ a ≤ r⁻¹ * b
a b r : ℝ≥0
hr : r ≠ 0
⊢ r * a ≤ b ↔ a ≤ r⁻¹ * b
have : 0 < r := lt_of_le_of_ne (zero_le r) hr.symm
no goals
a b r : ℝ≥0
hr : r ≠ 0
this : 0 < r
⊢ r * a ≤ b ↔ a ≤ r⁻¹ * b
rw [← mul_le_mul_left (inv_pos.mpr this), ← mul_assoc, inv_mul_cancel hr, one_mul]