«حكمه: لزوم العمل به والاعتقاد به، فجحوده كفر»
Its ruling is that performance and acceptance of its binding status are required; denying a definitively established obligation is described as disbelief.
The word juhud means denial of a known, decisive religious ruling, not simple negligence in performance. Neglecting a duty and denying that it is a duty are two different matters.
The textbook is setting out a legal-theoretical classification, not authorizing an automatic judgment against an individual. Questions about an identifiable person require further conditions, evidence and scholarly examination.