English
Every model of the preorder theory carries a preorder structure, i.e. the relation interpreted as ≤ is reflexive and transitive.
Русский
Каждая модель теории предведенного порядка обладает структурой preorder; отношение ≤ рефлексивно и транзитивно.
LaTeX
$$$ \text{Preorder } M $$$
Lean4
/-- Any model of a theory of preorders is a preorder. -/
def preorderOfModels [h : M ⊨ L.preorderTheory] : Preorder M
where
__ := L.leOfStructure M
le_refl :=
Relations.realize_reflexive.1
((Theory.model_iff _).1 h _ (by simp only [preorderTheory, Set.mem_insert_iff, Set.mem_singleton_iff, true_or]))
le_trans :=
Relations.realize_transitive.1
((Theory.model_iff _).1 h _ (by simp only [preorderTheory, Set.mem_insert_iff, Set.mem_singleton_iff, or_true]))