how to proove wheter a worker has actually finished a job?
as this question probaply already tells, i dont have a good idea of mining pools and stuff. 

so from my understanding, a job is essentially a task for a miner in the pool to hash a transaction in combination with all nonces from value x to value y, and returns only correct hashs. is this understanding even right in the first place? but my main question is, how does the proxy know, that the miner has actually finished the job work, and doesnt just pretend that he did. 

if i am having any wrong expectations in the first place, please go ahead and correct me, i am fairly new to crypto