This is one of the stranger things I've heard about lately.

First, why in the world did you close on your purchase with a tenant in possession of the unit you were buying? Vacant possession should be a prerequisite to any sale except in extraordinary circumstances - e.g., buying an apartment with a rent-controlled tenant as an investment.

Second, you can give someone a general warning in writing that rules will be enforced, but that's not a "written warning" in the usual sense of the term. The warning has to *follow* the specific offense. This is confirmed by the language in the House Rules you cite: "First Offense: written warning (see above)." Note that the penalty on each line follows as a *consequence* of the offense. However, as sleazy as this may be, it's not terribly important because House Rules are generally subject to change by a vote of the board. They can change the language in the House Rule to match what they want it to say.

The third point is that the authority to impose financial penalties must come from the Proprietary Lease, not the House Rules. Financial penalties are a material term of the lease and may not be imposed unilaterally by the board. The board can add financial penalties to the House Rules, but they will not be enforceable unless the lease clearly provides for such penalties.

All that said, I would make two recommendations. First, CONSULT YOUR ATTORNEY as it sounds like this is quite a bad situation for everyone. (I must stress that I am not an attorney myself.) Second, look for an amicable solution to this mess. Both you and the board are very unhappy about the situation, and you should be actively working to remove the tenant while reassuring the board that you are doing so.