How do I approach finding a simplified function of an 8 variable boolean function given a truth table
Solution 1:
If I understand your notation (comparators aren't used in boolean expressions), your question is quasi-trivial. Minterms are
$$ABCD+\overline{WXYZ}=ABCD+\overline W+\overline X+\overline Y+\overline Z$$
$$\overline{ABCD}+WXYZ=\overline A+\overline B+\overline C+\overline D+WXYZ$$