order, strict partial order, non-strict partial order, strict total order, non-strict total order

An order  is a relation R that satisfies transitivity. i.e., such that if aRb and bRc, then aRc.

A strict partial order is a relation < on S that satisfies irreflexivity(\(\forall x\in S \lnot x<x\)) and transitivity(\(\forall x,y,z \in S, x<y\land y<z \rightarrow x<z\))

We can define a new relation \(\leq\) based on any relation <: \( x\leq y\leftrightarrow x<y \lor x=y\)

If < is a strict partial order, the defined  \(\leq\) is called non-strict partial order.

From the properties of strict partial order <, we can derive the following properties of the non-strict partial \(\leq\):

  • relexivity: \(\forall x \in S, x\leq x\)
  • transitivity: \(\forall x,y,z \in S, x\leq y\land y\leq z \rightarrow x\leq z\)
  • antisymmetry: \(\forall x,y \in S, x\leq y\land y\leq x \rightarrow x=y\)

Both strict partial order and non-strict partial order are partial order.

A strict total order is a strict partial order < that also satisfies \(\forall x,y \in S x<y\lor x=y\lor y<x\).

A non-strict total order is a non-strict partial order \(\leq\) that also satisfies \(\forall x,y \in S x\leq y\lor x=y\lor y\leq x\).

Both strict total order and non-strict total order are total order.

References:

https://en.wikipedia.org/wiki/Total_order

https://en.wikipedia.org/wiki/Partially_ordered_set

 

Did you like this?
Tip admin with Cryptocurrency

Donate Bitcoin to admin

Scan to Donate Bitcoin to admin
Scan the QR code or copy the address below into your wallet to send some bitcoin:

Donate Bitcoin Cash to admin

Scan to Donate Bitcoin Cash to admin
Scan the QR code or copy the address below into your wallet to send bitcoin:

Donate Ethereum to admin

Scan to Donate Ethereum to admin
Scan the QR code or copy the address below into your wallet to send some Ether:

Donate Litecoin to admin

Scan to Donate Litecoin to admin
Scan the QR code or copy the address below into your wallet to send some Litecoin:

Donate Monero to admin

Scan to Donate Monero to admin
Scan the QR code or copy the address below into your wallet to send some Monero:

Donate ZCash to admin

Scan to Donate ZCash to admin
Scan the QR code or copy the address below into your wallet to send some ZCash:

Leave a Reply