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 | Allegro CL | 

 
 
 
 
 

 

 
 
| ANSI Common Lisp  14 Conses  14.1 Cons Concepts  14.1.1 Conses as Trees 14.1.1.1 General Restrictions on Parameters that must be TreesExcept as explicitly stated otherwise, for any standardized function that takes a parameter that is required to be a tree, the consequences are undefined if that tree is circular. | 

 
 
 
 
 

 

 
