English
The StarModule structure provides a strict monotonicity of smul when the scalar is positive.
Русский
Структура StarModule обеспечивает строгую монотонность умножения на положительный скаляр.
LaTeX
$$PosSMulStrictMono(R,A)$$
Lean4
instance : PosSMulStrictMono R A where
smul_lt_smul_of_pos_left r hr a b
hab := by
rw [StarOrderedRing.pos_iff] at hr
rw [StarOrderedRing.lt_iff] at hab ⊢
obtain ⟨a, ha₀, ha, rfl⟩ := hab
obtain ⟨hr₀, hr⟩ := hr
exact ⟨r • a, smul_ne_zero hr₀ ha₀, smul_mem_closure_star_mul hr ha, smul_add ..⟩