If ``h'' is selected in #13.6, the hex expression of the current rule is displayed. The hex character to be updated is highlighted by a green flashing cursor, which can be moved with the arrow keys. The left/right/up/down arrow keys are use to displace the cursor. The up/down arrow keys only apply for rules where k>=8, where the hex digits are presented in 2 or 4 rows. To overwrite, enter a hex character (1-9, a-f, without ut ``return``) from the keyboard. This automatically moves the cursor one position to the right.
A top right reminder window displays the following,
enter hex, arrows-move
rotate-l/r, accept-ret
The rule can be rotated as in #13.10. To accept the hex expression of the rule table bit pattern, enter ``return``. Once selected, the rule is also displayed in decimal (for n<=5) and as the rule table bit pattern, and in the rule window.