The inequalities among the ideals of measure (null sets) and category (meagre sets) are captured in Cichon's diagram. Seventeen models (forcing constructions) were produced during the 1980s, starting with work of Arnold Miller, to demonstrate that no other inequalities are provable.
The disparities between measure ideals (null sets) and category ideals (meagre sets) are illustrated in Cichon's diagram. Seventeen models (forcing constructions) were developed during the 1980s, beginning with Arnold Miller’s work, to show that no other inequalities can be proven.