Description: 2 is an integer greater than or equal to 1. (Contributed by Alexander van der Vekens, 8-Jun-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 2eluzge1 | |- 2 e. ( ZZ>= ` 1 ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 1z | |- 1 e. ZZ | |
| 2 | 2z | |- 2 e. ZZ | |
| 3 | 1le2 | |- 1 <_ 2 | |
| 4 | eluz2 | |- ( 2 e. ( ZZ>= ` 1 ) <-> ( 1 e. ZZ /\ 2 e. ZZ /\ 1 <_ 2 ) ) | |
| 5 | 1 2 3 4 | mpbir3an | |- 2 e. ( ZZ>= ` 1 ) |