context | X |
definiendum | ≤ ∈ it |
The relation ≤ is an order relation if it's in the intersection of all total, all anti-symmetric and all transitive relation. Hence
context | ≤ ∈ Rel(X) |
x,y,z∈X |
postulate | x≤y ∨ y≤x |
postulate | x≤y ∧ y≤x⟹(x=y) |
postulate | x≤y ∧ y≤z⇔x≤z |
Wikipedia: Total order