kdrag.theories.real.lim_algebra

Algebra of real sequence limits.

Theorem

Statement

real.lim_algebra.abs_add

∀x y : ℝ, |x + y| ≤ |x| + |y|

real.lim_algebra.abs_div

∀x y : ℝ, y ≠ 0 → |x / y| = |x| / |y|

real.lim_algebra.abs_mul

∀x y : ℝ, |x * y| = |x| * |y|

real.lim_algebra.abs_neg

∀x : ℝ, |-x| = |x|

real.lim_algebra.abs_pos

∀x : ℝ, |x| ≥ 0

real.lim_algebra.abs_pos_iff

∀x : ℝ, (|x| > 0) = (x ≠ 0)

real.lim_algebra.abs_triangle

∀x y z : ℝ, |x - y| ≤ |x - z| + |z - y|

real.lim_algebra.div_decomp

∀u v w z : ℝ,   v ≠ 0 ∧ z ≠ 0 →   u / v + -1 * (w / z) = (u - w) / v + w * ((z - v) / (v * z))

real.lim_algebra.has_lim_add

∀a b : ℤ → ℝ, x y : ℝ,   has_lim(a, x) → has_lim(b, y) → has_lim(a + b, x + y)

real.lim_algebra.has_lim_div

∀a b : ℤ → ℝ, x y : ℝ,   has_lim(a, x) →   has_lim(b, y) → y ≠ 0 → has_lim(a / b, x / y)

real.lim_algebra.has_lim_mul

∀a b : ℤ → ℝ, x y : ℝ,   has_lim(a, x) → has_lim(b, y) → has_lim(a * b, x * y)

real.lim_algebra.has_lim_smul

∀a : ℤ → ℝ, x c : ℝ,   has_lim(a, x) → has_lim(RSeq.smul(c, a), c * x)

real.lim_algebra.lim_of_nonneg_seq

∀a : ℤ → ℝ, y : ℝ,   has_lim(a, y) → (∀n : ℤ, n ≥ 0 → a[n] ≥ 0) → y ≥ 0