Complex sentence: The work remained a unfinished of just "Kyrie" and a fragment of a "Dies irae" and was later assigned the name and work number "Lateinisches Requiem", op.145a.
Split into simpler sentences: The work remained unfinished, just a "Kyrie" and a fragment of a "Dies Irae". The "Kyrie" was later assigned the name and work number "Lateinisches Requiem", op.145a.