Exercises
[21Y]Prerequisites:[071],[07V].Let \((X_ 1,≤_ 1)\), \((X_ 2,≤_ 2)\) be two disjoint and partially ordered sets and with the same order type. Let \(I=\{ 1,2\} \) with the usual order; let \(Z=I× X_ 1\) equipped with lexicographical order; Let \(W\) be the concatenation of of \(X_ 1\) with \(X_ 2\): show that \(Z\) and \(W\) have the same type of order.
Solution 1