anchor.diff:     CASE
      1 OF aligned @ . ENDOF
      2 OF aligned dup cell+ swap @ swap . . ENDOF
  -   3 OF count type ENDOF
  +   3 OF aligned dup @ >r cell+ r> type ENDOF
      4 OF c@ IF ." true" ELSE ." false" THEN ENDOF
      5 OF c@ . ENDOF \ XXX: print symbolically
      ENDCASE
  
positive.code:    CASE
     1 OF aligned @ (.d) ENDOF
     2 OF drop 0 0 ENDOF
     3 OF count ENDOF
     4 OF c@ IF s" true" ELSE s" false" THEN ENDOF
     5 OF c@ (.) ENDOF \ XXX: print symbolically
     ENDCASE
  
negative.code:    2 c, align dup , here swap dup allot move
     DOES> char+ aligned dup @ >r cell+ r>
  ;
  : env-string  ( str len -- )  3 c, align dup , here over allot swap move DOES> char+ aligned dup @ >r cell+ r> ;
  : env-flag    ( f -- )  4 c, c, DOES> char+ c@ 0<> ;
  : env-secmode ( sm -- )  5 c, c, DOES> char+ c@ ;
  
  