Natural Number m is Less than n implies n is not Greater than Successor of n

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Theorem

Let $\N$ be the natural numbers.

Let $m, n \in \N$.

Then:

$m < n \implies m + 1 \le n$


Proof using Naturally Ordered Semigroup

Let $\N$ be considered as the naturally ordered semigroup:

$\struct {\N, +, \le}$

The result follows from Sum with One is Immediate Successor in Naturally Ordered Semigroup.


Proof using Von Neumann Construction

Let $\N$ be defined as the von Neumann construction $\omega$.

By definition of the ordering on von Neumann construction:

$m \le n \iff m \subseteq n$

From Von Neumann Construction of Natural Numbers is Minimally Inductive, $\omega$ is minimally inductive class under the successor mapping.

The result is then a direct application of Characteristics of Minimally Inductive Class under Progressing Mapping: Image of Proper Subset is Subset:

$m \subset n \implies m^+ \subseteq n$

$\blacksquare$