> For the complete documentation index, see [llms.txt](https://mandober.gitbook.io/math-debrief/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mandober.gitbook.io/math-debrief/900-index/enums/enum-logic-formulas.md).

# Math › Logic formulae

Formulas of predicate, mostly FOL, logic that express common mathematical notions. Formulae are given loosely, avoring the succinct loose-math-system to the stricter, FOL system, that relies on predicates excessively. The canonical example of this is `∀x ∈ ℕ` (math-loose) vs `∀x.P(x)` (strict-FOL) with the predicate `P` standing for the property of "being a natural number".