# Named Relations

* `=`   EQ, "is equal to", x = y
* `≠`   NE
* `<=`  LE
* `<`   LT
* `>=`  GE
* `>`   GT
* `⊆`   set inclusion (containment) relation: "is a subset of", x ⊆ y
* `∈`   set membership relation: "is a memeber of", x ∈ y
* `∣`    divisibility, `a ∣ b`, `a ∤ b` , a ∣ b -> m ∈ Z. ma <= b
* `max`
* `min`
* typing relation
* universal relation, U = S²
* diagonal (identity) pairs only, ∆s
* converse (inverse, transpose) relation, R⁻¹
* empty relation, Rₛ = ∅
* functional, right-unique
* serial, left-
