Skip to main content
YaelDillies/APAP
Source indexedlemma · leanprover/lean4:v4.32.0

curlog_mul_le

APAP.FiniteField · APAP/FiniteField.lean:80 to 90

Mathematical statement

Exact Lean statement

lemma curlog_mul_le (hx₀ : 0 < x) (hx₁ : x ≤ 1) (hy₀ : 0 < y) (hy₁ : y ≤ 1) :
    𝓛 (x * y) ≤ x⁻¹ * 𝓛 y

Complete declaration

Lean source

Canonical source
Full Lean sourceLean 4
lemma curlog_mul_le (hx₀ : 0 < x) (hx₁ : x  1) (hy₀ : 0 < y) (hy₁ : y  1) :    𝓛 (x * y)  x⁻¹ * 𝓛 y := by  suffices h : log x⁻¹ - (x⁻¹ - 1)  (x⁻¹ - 1) * log y⁻¹ by    rw [ sub_nonneg] at h     convert h using 1    rw [mul_inv, log_mul]    any_goals positivity    ring  calc    log x⁻¹ - (x⁻¹ - 1)  0 := sub_nonpos.2 <| log_le_sub_one_of_pos <| by positivity    _  (x⁻¹ - 1) * log y⁻¹ := mul_nonneg (sub_nonneg.2 <| (one_le_inv₀ hx₀).2 hx₁) <| by bound