I was trying to manipulate with litarals and minterms of this booleans expression but it really did not lead to anything that could simplify the expression further.. Not sure if I am doing it wrong or it indeed cannot be simplified any further.
$$x_1'x_2'x_3 + x_1'x_2x_3'+x_1x_2'x_3' + x_1x_2x_3$$
well, I can do $$x_1(x_2'x_3' + x_2x_3) + x_1'(x_2'x_3 + x_2x_3')$$ I was thinking if expressions in parenthesis can be simplified and I was looking for appropriate identities.. but it seems they cannot be simplified, there is no tautology. Thus, I stuck here and I believe this expression cannot be simplified really. Right?