Metamath Proof Explorer


Theorem onsucss

Description: If one ordinal is less than another, then the successor of the first is less than or equal to the second. Lemma 1.13 of Schloeder p. 2. See ordsucss . (Contributed by RP, 16-Jan-2025)

Ref Expression
Assertion onsucss
|- ( A e. On -> ( B e. A -> suc B C_ A ) )

Proof

Step Hyp Ref Expression
1 eloni
 |-  ( A e. On -> Ord A )
2 ordsucss
 |-  ( Ord A -> ( B e. A -> suc B C_ A ) )
3 1 2 syl
 |-  ( A e. On -> ( B e. A -> suc B C_ A ) )