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 ) |