HP 35s HP 35s scientific calculator - User Guide - Page 348

Indicates the "top" of equation memory. The memory scheme is circular, so is also the "equation" after the last equation in equation memory. The calculator is calculating the integral of an equation or program. This might take a while. A running CALCULATE,SOLVE or ∫ FN operation was interrupted by pressing  or  in ALG, RPN, EQN, or PGM mode. Data error: Attempted to save or calculate error data. Attempted to calculate combinations or permutations with r >n, with non-integer r or n, or with n ≥1016. Attempted to save a complex number or vector in the statistical data. Attempted to save a base-n number that contains digits greater than the largest base-n number digit allowed. Attempted to save an invalid data in the statistical register using operation. Attempt to compare complex numbers or vectors. Attempted to use a trigonometric or hyperbolic function with an illegal argument:  with x an odd multiple of 90°.  or  with x < -1 or x > 1. with x ≤ -1; or x ≥ 1. with x < 1. Attempted to enter an invalid variable name when solving an equation. Attempted a factorial or gamma operation with x as a negative integer. F-2 Messages