Lean4
instance : CompleteLattice (Concept α β r) :=
{ Concept.instLatticeConcept,
Concept.instBoundedOrderConcept with
sup := Concept.instSupConcept.max
le_sSup := fun _ _ hc => intent_subset_intent_iff.1 <| biInter_subset_of_mem hc
sSup_le := fun _ _ hc =>
intent_subset_intent_iff.1 <| subset_iInter₂ fun d hd => intent_subset_intent_iff.2 <| hc d hd
inf := Concept.instInfConcept.min
sInf_le := fun _ _ => biInter_subset_of_mem
le_sInf := fun _ _ => subset_iInter₂ }