Metamath Proof Explorer


Theorem upwrdfi

Description: There is a finite number of strictly increasing sequences of a given length over finite alphabet. Trivially holds for invalid lengths where there're zero matching sequences. (Contributed by Ender Ting, 5-Jan-2024)

Ref Expression
Assertion upwrdfi S Fin a UpWord S | a = T Fin

Proof

Step Hyp Ref Expression
1 wrdnfi S Fin a Word S | a = T Fin
2 upwordisword a UpWord S a Word S
3 2 ad2antrl a UpWord S a = T a Word S
4 3 rabss3d a UpWord S | a = T a Word S | a = T
5 4 mptru a UpWord S | a = T a Word S | a = T
6 ssfi a Word S | a = T Fin a UpWord S | a = T a Word S | a = T a UpWord S | a = T Fin
7 5 6 mpan2 a Word S | a = T Fin a UpWord S | a = T Fin
8 1 7 syl S Fin a UpWord S | a = T Fin