   ACCEPT identifier-1
   ~~~~~~
          FROM { ENVIRONMENT-VALUE            }
          ~~~~ { ~~~~~~~~~~~~~~~~~            }
               { ENVIRONMENT { literal-1    } }
               { ~~~~~~~~~~~ { identifier-1 } }
        [ ON EXCEPTION imperative-statement-1 ]
             ~~~~~~~~~
        [ NOT ON EXCEPTION imperative-statement-2 ]
          ~~~    ~~~~~~~~~
 [ END-ACCEPT ]
   ~~~~~~~~~~
