%%HP: T(3)A(R)F(.);
\<<
  \<< DUP
    IF 9. \<=
    THEN SWAP "0" + SWAP
    END R\->I \->STR
  \>> \-> z0
  \<< ROT R\->I \->STR "-" + ROT z0 EVAL "-" + + SWAP z0 EVAL +
  \>>
\>>