asymptote: plain

 
 8.1 'plain'
 ===========
 
 This is the default 'Asymptote' base file, which defines key parts of
 the drawing language (such as the 'picture' structure).
 
    By default, an implicit 'private import plain;' occurs before
 translating a file and before the first command given in interactive
 mode.  This also applies when translating files for module definitions
 (except when translating 'plain', of course).  This means that the types
 and functions defined in 'plain' are accessible in almost all
 'Asymptote' code.  Use the '-noautoplain' command-line option to disable
 this feature.