Complex sentence: The earliest computers were programmed in their native assembly language, which is inherently reflective as it is programmed by defining the instructions as data, allowing it therefore to be accessed so, and reflective functionality such as modifying the instructions or analysing them was commonplace.
Split into simpler sentences: The earliest computers were programmed in their native assembly language, which is inherently reflective as it is programmed by defining the instructions as data. Reflective functionality such as modifying the instructions or analysing them was commonplace.