What has to be the general and final formula for calculating the effective memory access time, taking in consideration the $\alpha$-level page table, TLB hit ratio as $h$, miss ratio as $m$, memory access time as $M$, TLB access time as $T$, page fault probability as $p$ and time for page fault servicing as $x$? There seems to be so many formulae, each different from each other depending on the question.