Metamath Proof Explorer


Theorem naddword2

Description: Weak-ordering principle for natural addition. (Contributed by Scott Fenton, 15-Feb-2025)

Ref Expression
Assertion naddword2
|- ( ( A e. On /\ B e. On ) -> A C_ ( B +no A ) )

Proof

Step Hyp Ref Expression
1 naddword1
 |-  ( ( A e. On /\ B e. On ) -> A C_ ( A +no B ) )
2 naddcom
 |-  ( ( A e. On /\ B e. On ) -> ( A +no B ) = ( B +no A ) )
3 1 2 sseqtrd
 |-  ( ( A e. On /\ B e. On ) -> A C_ ( B +no A ) )