It has the simplest form: it
dir Pattern1,Pattern2,Pattern3 >nul 2>&1 && echo found
dirwill search for files or directories matching the given templates (you can use wildchars). If you want only files, use dir /A-D
>nul 2>&1canceling the output from it
&&means execution only if the previous command was successful (that is, dir found the / dir file with this template). You can also use the ||value opposite (if the previous failure).
, , :
(dir Pattern1 && dir Pattern2 && dir Pattern3) >nul 2>&1 && echo found
, (!), if errolevel/if not errorlevel.
dir 1, , 0, .
, echo