%%HP: T(3)A(D)F(.);
\<<
  IF 4 FS?
  THEN
  ELSE CBM
  END 4 CF fy 87000
+ INV 87000 * .85 *
\Gb1 * fc * fy / '\Grb'
STO As b / d / '\Gr'
STO
  IF '\Gr>.75*\Grb'
  THEN
"Error:  \Gr max!"
DOERR
  END
  IF '200/fy>\Gr'
  THEN
"Check cracking moment!"
CLLCD 1 DISP 1
FREEZE
  END As fy * .85 /
fc / b / 'a' STO a
2 / NEG d + fy * As
* .9 * 12000 / 'Mu'
STO Mu "Mu(k-ft)"
\->TAG 1 CF
\>>
