Formally, null can be defined as empty tuple NULL=⧼⧽ as opposed to normal values which are non-empty tuples like ⧼5.0⧽. It is analogous to having empty set ∅={}

Formally, null can be defined as empty tuple NULL=⧼⧽ as opposed to normal values which are non-empty tuples like ⧼5.0⧽. It is analogous to having empty set ∅={} and non-empty sets {5.0, 6.0, ...}. TUPLES SETS NULL=⧼⧽ ∅={} combinations collections Obviously, there is duality between tuples and sets but currently there is no theory which would be based on this property by treating them as equal constructs (tuples are defined as ordered sets by simply ignoring their duality to sets). Since variables need to allocate some memory to store their values, it is necessary to introduce a mechanism to deal with empty values and then somehow interpret them. There was another discussion of nulls some time ago: https://news.ycombinator.com/item?id=17028878 https://news.ycombinator.com/item?id=17028878 (The Logical Disaster of Null)