Builder enters into a signed written enforceable contract with Homeowner to build Homeowner an in$-$ground swimming pool at a total contract price of $\backslash$$$40,000.$ After construction has begun but before it is complete, Homeowner tells Builder that he has just been laid off from his job and instructs Builder to stop work on the swimming pool. Homeowner acknowledges that he is in breach of contract and asks Builder to let him know what compensatory damages he owes Builder. The following is the Builder's construction budget: Note the following additional facts:

$-$ At the time Homeowner instructed Builder to stop work on the project, the excavation was complete and Builder had paid Ace Excavation the total sum due under the excavation subcontract.

$-$ At the time Homeowner instructed Builder to stop work on the project, Builder had not yet entered into a contract with Beta Concrete nor had he ordered the materials for the pool, pool deck or any of the landscaping materials.

$-$ In addition, you can assume that after Homeowner instructed Builder to stop work on the project, Builder tried but was unable to mitigate his damages by finding a substitute construction job for the same time period.

a$.$ What amount of compensatory damages is Builder entitled to recover from Homeowner under these circumstances? Show your calculations.

b$.$ If all of the above facts remained the same, $($Ace Excavation completed the excavation work under its contract with Builder$)$ but Builder had not yet paid Ace Excavation the $\backslash (\backslash$$ $12,000\backslash )$ due under the excavation subcontract, what amount of compensatory damages would Builder be entitled to recover from Homeowner? Show your calculations.