Description: A positive integer which is not 1 is greater than or equal to 2. (Contributed by Glauco Siliprandi, 11-Dec-2019)
Ref | Expression | ||
---|---|---|---|
Assertion | nnne1ge2 | |- ( ( N e. NN /\ N =/= 1 ) -> 2 <_ N ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nnnn0 | |- ( N e. NN -> N e. NN0 ) |
|
2 | 1 | adantr | |- ( ( N e. NN /\ N =/= 1 ) -> N e. NN0 ) |
3 | nnne0 | |- ( N e. NN -> N =/= 0 ) |
|
4 | 3 | adantr | |- ( ( N e. NN /\ N =/= 1 ) -> N =/= 0 ) |
5 | simpr | |- ( ( N e. NN /\ N =/= 1 ) -> N =/= 1 ) |
|
6 | nn0n0n1ge2 | |- ( ( N e. NN0 /\ N =/= 0 /\ N =/= 1 ) -> 2 <_ N ) |
|
7 | 2 4 5 6 | syl3anc | |- ( ( N e. NN /\ N =/= 1 ) -> 2 <_ N ) |