How to compare / check several TVs for fullness in MODx and display the result of the comparison?

Question

MODX

Greetings
I do not understand how to implement a check of several TV parameters in MODx and, depending on the comparison, display something on the screen. Tell me please.
For example, let's take two TVs - ONE = 'one' & TWO = ''.
Checking one parameter works: But beyond this, difficulties arose. Please explain with an example how to implement the following:
if TV.ONE == empty OR not empty, then output or not output something
(if TV.ONE == empty) AND (TV.TWO not empty), then output or not we deduce something
Some kind of trouble ...
PS
I tried like this, but in vain:

Answer 1

Write a simple snippet

<?php
if(!empty(trim($input))) return $then;