Can't you just implement a turing machine in Excel by using the cells in a row as your tape? * Store the initial internal state in A1. * Store the initial hea

Can't you just implement a turing machine in Excel by using the cells in a row as your tape? * Store the initial internal state in A1. * Store the initial head position B1. * Store the initial state as boolean values in the rest of row 1. * Write simple lookup formulas in row 2 to compute the next state from the previous row. * Fill down. Look for the halting state in column A and your output will be written in that row. What am I missing?