%%HP: T(3)A(R)F(.);
\<< DTAG SWAP DTAG SWAP
  \<<
    IF
      IF DUP TYPE 9. -
      THEN 0.
      ELSE DUP \->LST DUP 1.
        \<< TYPE
        \>> DOSUBS R\->I { 28 28 18 } SAME SWAP DUP SIZE GET { / } 1. GET SAME AND
      END
    THEN FXND
    ELSE
      IF DUP FXND MOD
      THEN 11. OVER XPON - ALOG SWAP OVER * R\->I SWAP R\->I SIMP2
      ELSE 1
      END
    END
  \>> \-> tof
  \<<
    IF OVER TYPE 2. SAME
    THEN SWAP DUP "." POS DUP2 1. - 1. SWAP SUB PICK3 PICK3 1 + OVER SIZE SUB + STR\-> ROT SIZE ROT - R\->I ALOG / SWAP
    END
    IF OVER FXND MOD 0 \=/
    THEN
      IF DUP 1 \>= OVER TYPE 28. SAME AND
      THEN NEG ALOG
      END tof EVAL ROT tof EVAL DUP2 0 1 \-> a b n0 d0 n d cd pd
      \<< 1 d0 a *
        DO pd cd DUP 'pd' STO n d DUP 'n' STO IDIV2 'd' STO * + 'cd' STO SWAP NEG SWAP
        UNTIL b d * OVER cd * \<=
        END DUP cd * b d * - SWAP pd * b n * + IQUOT n OVER * d + ROT * OVER NEG pd * cd + DUP2 n0 * + d0 ROT * SWAP OVER / UNROT /
        IF ROT 0 \=/
        THEN "X"
        ELSE "N"
        END \->TAG
      \>>
    ELSE DROP :N: 0
    END
  \>>
\>>