Funzione inversa Funzione inversa Da Wikipedia, l'enciclopedia libera. manda 3 in a poiché f manda a in 3 si dice invertibile se esiste una funzione
Omomorfismo Da Wikipedia, l'enciclopedia libera. è un omomorfismo se vale per ogni coppia di elementi di , dove e Omomorfismo
König's lemma König's lemma König's lemma or König's infinity lemma is a theorem in graph theory due to Dénes Kőnig (1936).[1] It gives a sufficient condition for an infinite graph to have an infinitely long path. The computability aspects of this theorem have been thoroughly investigated by researchers in mathematical logic, especially in computability theory. This theorem also has important roles in constructive mathematics and proof theory. Statement of the lemma[edit] Note that the vertex degrees must be finite, but need not be uniformly bounded: it is possible to have one vertex of degree 10, another of degree 100, a third of degree 1000, and so on. Proof[edit]
Modal Logic First published Tue Feb 29, 2000; substantive revision Fri Oct 2, 2009 A modal is an expression (like ‘necessarily’ or ‘possibly’) that is used to qualify the truth of a judgement. Modal logic is, strictly speaking, the study of the deductive behavior of the expressions ‘it is necessary that’ and ‘it is possible that’. Modal Logic
Click the W links for related Wikipedia articles If you have enjoyed this site, please show your appreciation by making a donation here to the Hope Projects, supporting and accommodating destitute and homeless asylum-seekers in the UK. Catch-22 There was only one catch and that was Catch-22, which specified that concern for one's own safety in the face of dangers that were real and immediate was the process of a rational mind. Orr was crazy and could be grounded.

Some paradoxes - an anthology

Some paradoxes - an anthology
Here are three paradoxes, all based on the same idea. 1. Let A be the set of all positive integers that can be defined in under 100 words. Since there are only finitely many of these, there must be a smallest positive integer n that does not belong to A. But haven't I just defined n in under 100 words? Richard's Paradox Richard's Paradox
Non solo matematica...
Funzione di Ackermann Da Wikipedia, l'enciclopedia libera. La funzione di Ackermann è una funzione f(x,y,z) che ha come dominio l'insieme delle terne di numeri naturali e come codominio i numeri naturali. Essa è definita per ricorrenza nel seguente modo: oppure: Funzione di Ackermann