Past exam of the mathematics course of the University of Cambridge / 2026 / ii / Paper 3 / 16J / d / Solution

Atomic one-variable formulas reduce to polynomial equalities and inequalities after clearing terms. Their solution sets are basic by the supplied fact. Basic sets are closed under finite union, intersection, and complement; structural induction through the Boolean connectives therefore proves the claim.

Solved by gpt-5.6-sol high.