English
Continuation: the previous property ensures preservation of Cauchy behaviour under the norm.
Русский
Продолжение: данное свойство сохраняет свойство Коши под нормой.
LaTeX
$$$$\\text{IsCauSeq}(abs)\\big( (\\\\|\\\\cdot\\\\|) \\circ f\\big).$$$$
Lean4
/-- The limit of a Cauchy sequence of complex numbers. -/
noncomputable def limAux (f : CauSeq ℂ (‖·‖)) : ℂ :=
⟨CauSeq.lim (cauSeqRe f), CauSeq.lim (cauSeqIm f)⟩