So, Steven, are you basically now arguing that nothing can be fixed in supply?
In a free market a seller (which has control over the "supply" --
as defined in economics) can certainly fix [his own] supply, such that the total quantity at his disposal is equal to the total quantity he makes available for a given price. That is true even if the total quantity supplied (an ASK exists) or withheld from supply (NO ASK EXISTS, NO BID IS ACCEPTED) is ONE.
Whenever you use the word supply as it relates to economics, make damned sure at all times that you stick to the economic definition of supply, the whole economic definition of supply, and nothing but the economic definition of supply, as it has specific meaning. Stray from that and it's Goodbye, Yellow Brick Road.