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 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0zd | |
|
2 | id | |
|
3 | 1 2 | fsnd | |
4 | fzo01 | |
|
5 | 4 | feq2i | |
6 | 3 5 | sylibr | |
7 | iswrdi | |
|
8 | 6 7 | syl | |