ENVIRONMENT?
* ENVIRONMENT? ( a1 n1 -- false | ?? true )

check the environment for a property, usually
a condition like questioning the existance of
specified wordset, but it can also return some
implementation properties like "WORDLISTS"
(the length of the search-order) or "#LOCALS"
(the maximum number of locals)
Here it implements the environment queries as a SEARCH-WORDLIST 

in a user-visible vocabulary called ENVIRONMENT
 : ENVIRONMENT?
   ['] ENVIRONMENT >WORDLIST SEARCH-WORDLIST
   IF  EXECUTE TRUE ELSE  FALSE THEN ;

FORTH/FORTH environ (dpANS.6.1.1345) ordinary primitive