Description: A singleton word is a word. (Contributed by Mario Carneiro, 26-Feb-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | s1cld.1 | |- ( ph -> A e. B ) |
|
| Assertion | s1cld | |- ( ph -> <" A "> e. Word B ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | s1cld.1 | |- ( ph -> A e. B ) |
|
| 2 | s1cl | |- ( A e. B -> <" A "> e. Word B ) |
|
| 3 | 1 2 | syl | |- ( ph -> <" A "> e. Word B ) |