The word thing represents an instance of the top concept "owl:Thing" and thus any variable in the SR-CE sentence. Used as a variable in semantic rules. If more variables of type thing appear, they can be enumerated by thing(n).
Those examples show how to use the word thing in semantic rules.
Example: In the semantic rule below, there is one variable which could be anything.
If a thing is a person then the thing has-name (some string value).
Example: In the semantic rule below, there are two variables 'thing'.
If a thing(1) hosts a thing(2) and the thing(2) hosts an application then the thing(1) hosts the application.