Metamath Proof Explorer


Theorem singoutnupword

Description: Singleton with character out of range S is not an increasing sequence for that range. (Contributed by Ender Ting, 22-Nov-2024)

Ref Expression
Hypothesis singoutnupword.1
|- A e. _V
Assertion singoutnupword
|- ( -. A e. S -> -. <" A "> e. UpWord S )

Proof

Step Hyp Ref Expression
1 singoutnupword.1
 |-  A e. _V
2 1 singoutnword
 |-  ( -. A e. S -> -. <" A "> e. Word S )
3 upwordisword
 |-  ( <" A "> e. UpWord S -> <" A "> e. Word S )
4 2 3 nsyl
 |-  ( -. A e. S -> -. <" A "> e. UpWord S )