Astra user reports filling gaps in books with clearly marked AI-written sections

A user says Astra worked “marvelously” at filling gaps in a book and describes adding clearly marked AI-generated sections without changing the original content. Their shared prompt asks for mathematical details in a history of tensor calculus, tailored to readers who understand differentiation, integration and basic 2D vectors. The user describes reading books with these additions as “10x more rewarding and enjoyable.”