arranging numbers with controller and data path

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as i said, the comparator only have 2 inputs

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My solution is still valid. For test1 you use one comparator to find max of A,B,C,D as follows:

you assign A to a register then you update that register if B > A (one comparator with two inputs).

then you update it again if C > B and again if D > C .

You then move to test2, test3

It is up to you to use state machine per comparison or you can do it all in one lump of logic.