Metamath Proof Explorer


Theorem snopiswrd

Description: A singleton of an ordered pair (with 0 as first component) is a word. (Contributed by AV, 23-Nov-2018) (Proof shortened by AV, 18-Apr-2021)

Ref Expression
Assertion snopiswrd
|- ( S e. V -> { <. 0 , S >. } e. Word V )

Proof

Step Hyp Ref Expression
1 0zd
 |-  ( S e. V -> 0 e. ZZ )
2 id
 |-  ( S e. V -> S e. V )
3 1 2 fsnd
 |-  ( S e. V -> { <. 0 , S >. } : { 0 } --> V )
4 fzo01
 |-  ( 0 ..^ 1 ) = { 0 }
5 4 feq2i
 |-  ( { <. 0 , S >. } : ( 0 ..^ 1 ) --> V <-> { <. 0 , S >. } : { 0 } --> V )
6 3 5 sylibr
 |-  ( S e. V -> { <. 0 , S >. } : ( 0 ..^ 1 ) --> V )
7 iswrdi
 |-  ( { <. 0 , S >. } : ( 0 ..^ 1 ) --> V -> { <. 0 , S >. } e. Word V )
8 6 7 syl
 |-  ( S e. V -> { <. 0 , S >. } e. Word V )