When users see one GUI as beautiful,
other user interfaces become ugly.
When users see some programs as winners,
other programs become lossage.

Pointers and NULLs reference each other.
High level and assembler depend on each other.
Double and float cast to each other.
High-endian and low-endian define each other.
While and until follow each other.

Therefore the Guru
programs without doing anything
and teaches without saying anything.
Warnings arise and he lets them come;
processes are swapped and he lets them go.
He has but doesn't possess,
acts but doesn't expect.
When his work is done, he deletes it.
That is why it lasts forever.