Interlock: never both open

Two doors, one vestibule: one leads into the workshop, the other outside into the dust storm. If both stand open at the same time, the storm blows right up to the workbench. An interlock makes sure only one door can be open at a time.

Ask first, then open#

A door may only open if the other one is closed. For that the chip reads the state of the other door, not the wish:

lbn shutOut DOOR HASH("Aussentuer") Open Average
seqz shutOut shutOut         # 1 = outer door is closed
and inner wantIn shutOut     # inner only if outer is closed

seqz turns “open = 0” into “closed = 1”. If the outer door is missing, its value is NaN, seqz returns 0, and the inner door stays closed. Unknown counts as open here, and that is the safe side.

Setting priority#

What if both wishes arrive in the same tick? Without a rule both doors read “the other one is closed” and open at the same time. That is why one door gets priority:

seqz tmp wantIn
and outer wantOut tmp        # outer only if inner wants nothing
and outer outer shutIn

Here the inner door wins. Whoever stands inside should not wait in front of a closed door.

Locking against manual use#

Players can also open a door by hand. Lock prevents that. Write Lock = 1 to every door that must not be open right now:

seqz tmp inner
sbn DOOR HASH("Innentuer") Lock tmp

Safe default state#

Without a wish, after a restart and with every missing value the rule is: both doors closed and locked. Build every rule so that a missing or unknown value leads exactly there.