%%HP: T(3)A(R)F(.);
@ FRAC, by Juergen Koslowski
\<< -3 CF NEG ALOG \-> a e
  \<< a ABS (0,1) (1,0)
    DO
      IF ROT DUP 1 <
      THEN 1 OVER - / 3 ROLLD OVER +
      ELSE 1 - OVER 4 ROLL + ROT
      END
    UNTIL DUP2 + C\->R / a ABS - ABS e <
    END + SWAP DROP C\->R # 5603Eh SYSEVAL a SIGN *
  \>>
\>>