Solve the following deduction problem. Show every inference step.

Four researchers — Alvarez, Brandt, Chen, and Dube — each work in exactly one of four buildings (North, South, East, West) and each studies exactly one topic (algae, basalt, comets, dialects). No two share a building or a topic.

Clues:
1. The person in North studies neither algae nor comets.
2. Chen works in neither South nor West.
3. The basalt researcher works directly east of the algae researcher. Among these four buildings, only East is directly east of West; North and South are neither east nor west of anything.
4. Brandt studies dialects.
5. Alvarez does not work in East.
6. Dube does not study comets.

Produce:
(a) The complete assignment of person, building, and topic.
(b) A numbered chain of deductions in which every step cites the clue number it uses. Each step must follow from clues and prior steps only.
(c) A statement of whether the solution is unique, with the reasoning that establishes uniqueness.
(d) Identify any clue that is logically redundant — one whose removal would not change the solution — and prove it is redundant.

If the constraints turn out to be contradictory, say so and name the minimal set of clues that conflict. Do not invent an assignment that satisfies only some of them.